diff --git a/include/dungeon_ai_attack.h b/include/dungeon_ai_attack.h
index 70781a844..99e9d5ac4 100644
--- a/include/dungeon_ai_attack.h
+++ b/include/dungeon_ai_attack.h
@@ -15,11 +15,6 @@ struct AIPossibleMove
 
 void ChooseAIMove(Entity *pokemon);
 s32 AIConsiderMove(struct AIPossibleMove *aiPossibleMove, Entity *pokemon, Move *move);
-bool8 IsTargetInLineRange(Entity *user, Entity *target, s32 range);
-s32 TryAddTargetToAITargetList(s32 numPotentialTargets, s32 targetingFlags, Entity *user, Entity *target, Move *move, u32 hasStatusChecker);
-bool8 IsAITargetEligible(s32 targetingFlags, Entity *user, Entity *target, Move *move, bool32 hasStatusChecker);
-s32 WeightMove(Entity *user, s32 targetingFlags, Entity *target, u32 moveType);
-bool8 TargetRegularAttack(Entity *pokemon, u32 *targetDir, bool8 checkPetrified);
 bool8 IsTargetInRange(Entity *pokemon, Entity *targetPokemon, s32 direction, s32 maxRange);
 void HandleUseMoveAIAction(Entity *target);
 void HandleUseOrbAction(Entity *pokemon);
diff --git a/include/dungeon_range.h b/include/dungeon_range.h
index cf726f30b..66c28756a 100644
--- a/include/dungeon_range.h
+++ b/include/dungeon_range.h
@@ -4,10 +4,10 @@
 #include "structs/str_position.h"
 #include "structs/dungeon_entity.h"
 
-bool8 IsPositionActuallyInSight(DungeonPos *pos1, DungeonPos *pos2);
-bool8 IsPositionInSight(DungeonPos *pos1, DungeonPos *pos2);
+bool8 IsPositionActuallyInSight(DungeonPos *origin, DungeonPos *target);
+bool8 IsPositionInSight(DungeonPos *origin, DungeonPos *target);
 void sub_80833E8(DungeonPos *param_1, s32 *param_2);
-bool8 IsTargetTwoTilesAway(DungeonPos *pos1, DungeonPos *pos2);
+bool8 IsPositionWithinTwoTiles(DungeonPos *pos1, DungeonPos *pos2);
 bool8 sub_8083568(s32 inX, s32 inY, u8 index);
 Entity* GetLeader(void);
 EntityInfo* GetLeaderInfo(void);
diff --git a/src/dungeon_ai_attack.c b/src/dungeon_ai_attack.c
index 0b48ce4c1..f0f0c3330 100644
--- a/src/dungeon_ai_attack.c
+++ b/src/dungeon_ai_attack.c
@@ -44,6 +44,12 @@ EWRAM_DATA u8 gPotentialAttackTargetDirections[NUM_DIRECTIONS] = {0};
 EWRAM_DATA s32 gPotentialAttackTargetWeights[NUM_DIRECTIONS] = {0};
 EWRAM_DATA Entity *gPotentialTargets[NUM_DIRECTIONS] = {0};
 
+static bool8 IsTargetInLineRange(Entity *user, Entity *target, s32 range);
+static s32 TryAddTargetToAITargetList(s32 numPotentialTargets, s32 targetingFlags, Entity *user, Entity *target, Move *move, bool32 hasStatusChecker);
+static bool8 IsAITargetEligible(s32 targetingFlags, Entity *user, Entity *target, Move *move, bool32 hasStatusChecker);
+static s32 WeightMove(Entity *user, s32 targetingFlags, Entity *target, u32 moveType);
+static bool8 TargetRegularAttack(Entity *pokemon, u32 *targetDir, bool8 checkPetrified);
+
 void ChooseAIMove(Entity *pokemon)
 {
     EntityInfo *pokemonInfo = GetEntInfo(pokemon);
@@ -526,59 +532,51 @@ s32 AIConsiderMove(struct AIPossibleMove *aiPossibleMove, Entity *pokemon, Move
     return moveWeight;
 }
 
-bool8 IsTargetInLineRange(Entity *user, Entity *target, s32 range)
+static bool8 IsTargetInLineRange(Entity *user, Entity *target, s32 range)
 {
     s32 direction;
     s32 distanceX = abs(user->pos.x - target->pos.x);
     s32 distanceY = abs(user->pos.y - target->pos.y);
     s32 distance = max(distanceX, distanceY);
 
-    if (distance > RANGED_ATTACK_RANGE || distance > range)
-    {
+    if (distance > RANGED_ATTACK_RANGE || distance > range) {
         return FALSE;
     }
     direction = -1;
-    if (distanceX == distanceY)
-    {
-        if (user->pos.x < target->pos.x &&
-            (user->pos.y < target->pos.y || user->pos.y > target->pos.y))
-        {
-            returnTrue:
-            return TRUE;
+    if (distanceX == distanceY) {
+        if (user->pos.x < target->pos.x && user->pos.y < target->pos.y) {
+            direction = DIRECTION_SOUTH;
         }
-        if (user->pos.x > target->pos.x); // Fixes register loading order.
-        direction = DIRECTION_SOUTHWEST;
-        if (user->pos.x <= target->pos.x || user->pos.y <= target->pos.y)
-        {
-            goto checkDirectionSet;
+        else if (user->pos.x < target->pos.x && user->pos.y > target->pos.y) {
+            direction = DIRECTION_EAST;
+        }
+        else if (user->pos.x > target->pos.x && user->pos.y > target->pos.y) {
+            direction = DIRECTION_NORTH;
+        }
+        else {
+            direction = DIRECTION_SOUTHWEST;
         }
-        goto returnTrue;
     }
-    else if (user->pos.x == target->pos.x && user->pos.y < target->pos.y)
-    {
-        return TRUE;
+    else if (user->pos.x == target->pos.x && user->pos.y < target->pos.y) {
+        direction = DIRECTION_SOUTH;
     }
-    else if (user->pos.x < target->pos.x && user->pos.y == target->pos.y)
-    {
-        return TRUE;
+    else if (user->pos.x < target->pos.x && user->pos.y == target->pos.y) {
+        direction = DIRECTION_SOUTHEAST;
     }
-    else if (user->pos.x == target->pos.x && user->pos.y > target->pos.y)
-    {
-        return TRUE;
+    else if (user->pos.x == target->pos.x && user->pos.y > target->pos.y) {
+        direction = DIRECTION_NORTHEAST;
     }
-    else if (user->pos.x > target->pos.x && user->pos.y == target->pos.y)
-    {
+    else if (user->pos.x > target->pos.x && user->pos.y == target->pos.y) {
         direction = DIRECTION_WEST;
     }
-    checkDirectionSet:
-    if (direction < 0)
-    {
-        return FALSE;
+
+    if (direction >= 0) {
+        return TRUE;
     }
-    return TRUE;
+    return FALSE;
 }
 
-s32 TryAddTargetToAITargetList(s32 numPotentialTargets, s32 targetingFlags, Entity *user, Entity *target, Move *move, bool32 hasStatusChecker)
+static s32 TryAddTargetToAITargetList(s32 numPotentialTargets, s32 targetingFlags, Entity *user, Entity *target, Move *move, bool32 hasStatusChecker)
 {
     s32 direction;
     s32 targetingFlags2 = (s16) targetingFlags;
@@ -607,7 +605,7 @@ s32 TryAddTargetToAITargetList(s32 numPotentialTargets, s32 targetingFlags, Enti
     return numPotentialTargets;
 }
 
-bool8 IsAITargetEligible(s32 targetingFlags, Entity *user, Entity *target, Move *move, bool32 hasStatusChecker)
+static bool8 IsAITargetEligible(s32 targetingFlags, Entity *user, Entity *target, Move *move, bool32 hasStatusChecker)
 {
     EntityInfo *targetData;
     s32 targetingFlags2 = (s16) targetingFlags;
@@ -733,7 +731,7 @@ bool8 IsAITargetEligible(s32 targetingFlags, Entity *user, Entity *target, Move
     return hasTarget;
 }
 
-s32 WeightMove(Entity *user, s32 targetingFlags, Entity *target, u32 moveType)
+static s32 WeightMove(Entity *user, s32 targetingFlags, Entity *target, u32 moveType)
 {
     EntityInfo *targetData;
     s32 targetingFlags2 = (s16) targetingFlags;
@@ -767,7 +765,7 @@ s32 WeightMove(Entity *user, s32 targetingFlags, Entity *target, u32 moveType)
     return weight;
 }
 
-bool8 TargetRegularAttack(Entity *pokemon, u32 *targetDir, bool8 checkPetrified)
+static bool8 TargetRegularAttack(Entity *pokemon, u32 *targetDir, bool8 checkPetrified)
 {
     EntityInfo *pokemonInfo = GetEntInfo(pokemon);
     s32 numPotentialTargets = 0;
diff --git a/src/dungeon_ai_movement.c b/src/dungeon_ai_movement.c
index 996117772..2dd6cf2d2 100644
--- a/src/dungeon_ai_movement.c
+++ b/src/dungeon_ai_movement.c
@@ -369,7 +369,7 @@ void DecideMovement(Entity *pokemon, bool8 showRunAwayEffect)
     if (ShouldAvoidFirstHit(pokemon, pokemonInfo->aiTarget.aiTargetingEnemy))
     {
         if (pokemonInfo->aiTarget.aiObjective == AI_CHASE_TARGET &&
-            IsTargetTwoTilesAway(&pokemon->pos, &pokemonInfo->aiTarget.aiTargetPos))
+            IsPositionWithinTwoTiles(&pokemon->pos, &pokemonInfo->aiTarget.aiTargetPos))
         {
             s32 distance = GetDistance(&pokemon->pos, &pokemonInfo->aiTarget.aiTargetPos);
             if (distance == 2)
diff --git a/src/dungeon_range.c b/src/dungeon_range.c
index 02b49c5ec..5434ad716 100644
--- a/src/dungeon_range.c
+++ b/src/dungeon_range.c
@@ -13,96 +13,70 @@
 
 EWRAM_INIT Entity *gLeaderPointer = NULL;
 
-bool8 IsPositionActuallyInSight(DungeonPos *pos1, DungeonPos *pos2)
+// Actual function in Sky. TODO: Find other uses of it and sync with Sky.
+static inline s32 GetVisibilityRange(void)
 {
-    u8 pos1Room;
-    u8 visibility = gDungeon->unk181e8.visibilityRange;
-    const Tile *tile1;
-    if (visibility == 0)
-    {
-        visibility = 2;
-    }
-    tile1 = GetTile(pos1->x, pos1->y);
-    pos1Room = tile1->room;
-    if (pos1Room == CORRIDOR_ROOM)
-    {
-        s32 xDiff = pos1->x - pos2->x;
-        s32 yDiff;
-        xDiff = xDiff < 0 ? -xDiff : xDiff;
-        if (xDiff > visibility)
-        {
-            return FALSE;
-        }
+    s32 visibilityRange = gDungeon->unk181e8.visibilityRange;
+    if (visibilityRange == 0)
+        return 2;
 
-        yDiff = pos1->y - pos2->y;
-        yDiff = yDiff < 0 ? -yDiff : yDiff;
-        if (yDiff > visibility)
-        {
-            return FALSE;
-        }
-        returnTrue:
-        return TRUE;
-    }
-    else
-    {
-        struct RoomData *pos1RoomData = &gDungeon->roomData[pos1Room];
-        if (pos1RoomData->bottomRightCornerX - 1 > pos2->x || pos1RoomData->bottomRightCornerY - 1 > pos2->y ||
-            pos1RoomData->topLeftCornerX + 1 <= pos2->x || pos1RoomData->topLeftCornerY + 1 <= pos2->y)
-        {
-            return FALSE;
-        }
-        goto returnTrue;
-    }
+    return visibilityRange;
 }
 
-bool8 IsPositionInSight(DungeonPos *pos1, DungeonPos *pos2)
+bool8 IsPositionActuallyInSight(DungeonPos *origin, DungeonPos *target)
 {
-  const Tile *tile;
-  u8 pos1Room;
-  s32 xDiff;
-  s32 yDiff;
-  s32 x1;
-  s32 x2;
-  s32 y1;
-  s32 y2;
-
-  tile = GetTile(pos1->x,pos1->y);
-  pos1Room = tile->room;
-  if (pos1Room != CORRIDOR_ROOM) {
-        struct RoomData *pos1RoomData = &gDungeon->roomData[pos1Room];
-        if (pos1RoomData->bottomRightCornerX - 1 > pos2->x || pos1RoomData->bottomRightCornerY - 1 > pos2->y ||
-            pos1RoomData->topLeftCornerX + 1 <= pos2->x || pos1RoomData->topLeftCornerY + 1 <= pos2->y)
-        {
-            goto _08083394;
-        }
-  }
-  else
-  {
-_08083394:
-
-    x1 = pos1->x;
-    x2 = pos2->x;
-
-    y1 = pos1->y;
-    y2 = pos2->y;
-
-    yDiff = y1 - y2;
-    xDiff = x1 - x2;
-
-    xDiff = xDiff < 0 ? -xDiff : xDiff;
-    yDiff = yDiff < 0 ? -yDiff : yDiff;
-
-    if (yDiff < xDiff) {
-      yDiff = xDiff;
+    s32 visibility = GetVisibilityRange();
+    const Tile *tile1 = GetTile(origin->x, origin->y);
+    u8 originRoom = tile1->room;
+    if (originRoom == CORRIDOR_ROOM) {
+        if (abs(origin->x - target->x) <= visibility && abs(origin->y - target->y) <= visibility)
+            return TRUE;
     }
-    if ((2 < yDiff))
-returnFalse:
+    else {
+        struct RoomData *originRoomData  = &gDungeon->roomData[originRoom];
+        if (originRoomData->bottomRightCornerX - 1 <= target->x &&
+            originRoomData->bottomRightCornerY - 1 <= target->y &&
+            originRoomData->topLeftCornerX + 1 > target->x &&
+            originRoomData->topLeftCornerY + 1 > target->y)
+            return TRUE;
+    }
+
+    return FALSE;
+}
+
+bool8 IsPositionInSight(DungeonPos *origin, DungeonPos *target)
+{
+    s32 diff;
+    const Tile *tile = GetTile(origin->x,origin->y);
+    u8 originRoom = tile->room;
+    if (originRoom != CORRIDOR_ROOM) {
+        struct RoomData *originRoomData = &gDungeon->roomData[originRoom];
+        if (originRoomData->bottomRightCornerX - 1 <= target->x &&
+            originRoomData->bottomRightCornerY - 1 <= target->y &&
+            originRoomData->topLeftCornerX + 1 > target->x &&
+            originRoomData->topLeftCornerY + 1 > target->y)
+            return TRUE;
+    }
+
+    // This looks like a static inline / macro, but I can't get it right for both Red/Sky. See also HandleCurvedProjectileThrow
+    {
+        s32 x = origin->x - target->x;
+        s32 y = origin->y - target->y;
+        s32 absX = abs(x);
+        s32 absY = abs(y);
+        diff = max(absX, absY);
+    }
+
+    if (diff > 2)
         return FALSE;
-    else if((yDiff == 2) && (!IsTargetTwoTilesAway(pos1,pos2))) {
-      goto returnFalse;
+    else if (diff == 2) {
+        if (IsPositionWithinTwoTiles(origin, target))
+            return TRUE;
+        else
+            return FALSE;
     }
-  }
-  return TRUE;
+
+    return TRUE;
 }
 
 void sub_80833E8(DungeonPos *param_1, s32 *param_2)
@@ -133,7 +107,7 @@ void sub_80833E8(DungeonPos *param_1, s32 *param_2)
   }
 }
 
-bool8 IsTargetTwoTilesAway(DungeonPos *pos1, DungeonPos *pos2)
+bool8 IsPositionWithinTwoTiles(DungeonPos *pos1, DungeonPos *pos2)
 {
     s32 i;
     const Tile *tile;