diff --git a/assets-cg/converters.py b/assets-cg/converters.py
index feccfd7..d0dc344 100644
--- a/assets-cg/converters.py
+++ b/assets-cg/converters.py
@@ -477,10 +477,16 @@ def convert_aseprite_anim_variation(input, output, params):
     else:
         raise fxconv.FxconvError(f"{input} lacks a 'palette:' metadata")
 
-    base = os.path.join(os.path.dirname(input), base)
-    palette = os.path.join(os.path.dirname(input), palette)
+    base_path = os.path.join(os.path.dirname(input), base)
+    palette_path = os.path.join(os.path.dirname(input), palette)
 
-    with open(palette, "rb") as fp:
+    base_metadata = os.path.join(os.path.dirname(input),
+        "fxconv-metadata.txt")
+    base_metadata = fxconv.Metadata(base_metadata).rules_for(base)
+
+    params = { **base_metadata, **params }
+
+    with open(palette_path, "rb") as fp:
         ase = AsepriteFile(fp.read())
 
     newpalette = None
@@ -490,7 +496,7 @@ def convert_aseprite_anim_variation(input, output, params):
     if newpalette is None:
         raise fxconv.FxconvError("f{input} has no palette chunk")
 
-    return convert_aseprite_anim(base, output, params, newpalette)
+    return convert_aseprite_anim(base_path, output, params, newpalette)
 
 def print_xml_tree(node, indent=0):
     print(indent*" " + f"<{node.tag}> {node.attrib}")
diff --git a/src/anim.c b/src/anim.c
index bb79b5b..107f3eb 100644
--- a/src/anim.c
+++ b/src/anim.c
@@ -95,7 +95,7 @@ fixed_t (anim_duration)(anim_t const *anim)
 
 bool anim_in(anim_frame_t const *frame, anim_t const *anim, int index)
 {
-    if(index >= anim->directions)
+    if(index >= anim->directions || !frame || !anim)
         return false;
 
     anim_frame_t *f = anim->start[index];
diff --git a/src/aoe.c b/src/aoe.c
index f4e36df..29d7884 100644
--- a/src/aoe.c
+++ b/src/aoe.c
@@ -86,6 +86,13 @@ entity_t *aoe_make_attack(uint16_t type, entity_t *origin, vec2 dir)
         distance = fix(0.375);
         lifetime = fix(999.0);
     }
+    else if(type == AOE_FIRE_CHARGE) {
+        anim = NULL;
+        hitbox = (rect){ -fix(12)/16, fix(12)/16, -fix(13)/16, fix(2)/16 };
+        distance = fix(0);
+        lifetime = fix(1.1);
+        rotate = false;
+    }
 
     p->x += fmul(distance, dir.x);
     p->y += fmul(distance, dir.y);
@@ -94,7 +101,13 @@ entity_t *aoe_make_attack(uint16_t type, entity_t *origin, vec2 dir)
 
     v->sprite_plane = plane;
 
-    aoe->lifetime = lifetime ? lifetime : anim_duration(anim);
+    if(lifetime)
+        aoe->lifetime = lifetime;
+    else if(anim)
+        aoe->lifetime = anim_duration(anim);
+    else
+        aoe->lifetime = fix(1.0);
+
     aoe->repeat_delay = 0;
     aoe->origin = origin;
 
@@ -127,6 +140,12 @@ entity_t *aoe_make_attack(uint16_t type, entity_t *origin, vec2 dir)
         v->z = fix(0.5);
         v->shadow_size = 4;
     }
+    else if(type == AOE_FIRE_CHARGE) {
+        aoe->data.charge.element = 0;
+        aoe->data.charge.power = f->MAG;
+        aoe->data.charge.origin = physical_pos(origin);
+        aoe->repeat_delay = fix(0.2);
+    }
 
     visible_set_anim(e, anim, 1);
     return e;
@@ -208,6 +227,14 @@ static bool attack_apply(game_t *game, aoe_t *aoe, entity_t *target)
         /* TODO: Sideways knockback */
         damage = aoe->data.bullet.strength * 2;
     }
+    else if(aoe->type == AOE_FIRE_CHARGE) {
+        dir.x = target_p->x - aoe->data.charge.origin.x;
+        dir.y = target_p->y - aoe->data.charge.origin.y;
+        dir = fnormalize(dir);
+        damage = aoe->data.charge.power * 3 / 2;
+        r /= 4;
+        fighter_stun(target, fix(0.1));
+    }
 
     /* Inflict damage */
     damage = fighter_damage(target, damage);
@@ -254,7 +281,8 @@ void aoe_apply(game_t *game, entity_t *entity, entity_t *e)
     || aoe->type == AOE_SLASH
     || aoe->type == AOE_IMPALE
     || aoe->type == AOE_SHOCK
-    || aoe->type == AOE_BULLET)
+    || aoe->type == AOE_BULLET
+    || aoe->type == AOE_FIRE_CHARGE)
         was_hit = attack_apply(game, aoe, e);
 
     if(aoe->type == AOE_JUDGEMENT) {
diff --git a/src/aoe.h b/src/aoe.h
index 5746696..4da0a47 100644
--- a/src/aoe.h
+++ b/src/aoe.h
@@ -23,6 +23,7 @@ enum {
     AOE_SHOCK,
     AOE_JUDGEMENT,
     AOE_BULLET,
+    AOE_FIRE_CHARGE,
     /* Spawn effect */
     EFFECT_SPAWN,
 };
@@ -63,6 +64,8 @@ typedef struct
         struct { int strength; vec2 origin; } shock;
         /* AOE_BULLET: magic strengh, speed parameters */
         struct { int strength; int dir; fixed_t v; fixed_t final_v; } bullet;
+        /* AOE_*_CHARGE: element type, origin and MAG power */
+        struct { int element; int power; vec2 origin; } charge;
     } data;
 
 } aoe_t;
diff --git a/src/comp/visible.c b/src/comp/visible.c
index 0d70fa4..1c63308 100644
--- a/src/comp/visible.c
+++ b/src/comp/visible.c
@@ -9,6 +9,11 @@ void visible_set_anim(entity_t *e, anim_t const *anim, int priority)
     if(priority < v->anim_priority)
         return;
 
+    if(anim == NULL) {
+        v->anim.frame = NULL;
+        return;
+    }
+
     int anim_index = 0;
     physical_t *p = getcomp(e, physical);
 
@@ -22,7 +27,7 @@ void visible_set_anim(entity_t *e, anim_t const *anim, int priority)
     if(anim_in(v->anim.frame, anim, anim_index))
         return;
 
-    v->anim.frame = anim->start[anim_index];
+    v->anim.frame = anim ? anim->start[anim_index] : NULL;
     v->anim.elapsed = 0;
     v->anim_priority = priority;
 }
@@ -30,6 +35,9 @@ void visible_set_anim(entity_t *e, anim_t const *anim, int priority)
 void visible_update(entity_t *e, fixed_t dt)
 {
     visible_t *v = getcomp(e, visible);
+    if(v->anim.frame == NULL)
+        return;
+
     anim_state_update(&v->anim, dt);
 
     if(v->anim.frame == NULL)
diff --git a/src/enemies.c b/src/enemies.c
index 13c485c..b6d824a 100644
--- a/src/enemies.c
+++ b/src/enemies.c
@@ -68,7 +68,7 @@ static enemy_t const bat_2 = {
 static enemy_t const fire_slime_4 = {
     .name = "Fire slime",
     .level = 4,
-    ANIMS(fire_slime, Idle, Walking, Idle, Hit, Death),
+    ANIMS(fire_slime, Idle, Walking, Attack, Hit, Death),
     .hitbox = (rect){ -fix(3)/16, fix(4)/16, -fix(2)/16, fix(3)/16 },
     .limits = {
         .max_speed = fix(1),
@@ -176,6 +176,9 @@ entity_t *enemy_make(int enemy_id)
         struct bat_ai *ai_data = f->enemy->ai_data;
         ai_data->retreat_period = 0;
     }
+    else if(enemy_id == ENEMY_FIRE_SLIME_4) {
+        f->skills[1] = AOE_FIRE_CHARGE;
+    }
     else if(enemy_id == ENEMY_GUNSLINGER_8) {
         f->skills[0] = AOE_PROJECTILE;
     }
@@ -287,8 +290,7 @@ static bool use_skill_towards_player(game_t *g, entity_t *e, int slot)
     vec2 dir = { player_p->x - p->x, player_p->y - p->y };
     dir = fnormalize(dir);
 
-    skill_use(g, e, slot, dir);
-    return true;
+    return skill_use(g, e, slot, dir);
 }
 
 void enemy_ai(game_t *g, entity_t *e, fixed_t dt)
@@ -318,7 +320,13 @@ void enemy_ai(game_t *g, entity_t *e, fixed_t dt)
 
     else if(f->enemy->id == &fire_slime_4) {
         if(move_within_range_of_player(g, e, fix(1.0), dt)) {
-            contact_attack(g, e);
+            /* Use the fire charge attack; if it fails, normal attack */
+            if(use_skill_towards_player(g, e, 1)) {
+                visible_set_anim(e, &anims_fire_slime_Fire, 2);
+            }
+            else {
+                contact_attack(g, e);
+            }
         }
     }
 
diff --git a/src/main.c b/src/main.c
index eea2417..db56d6a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -360,7 +360,7 @@ int main(void)
             }
             if(ev.key == KEY_F4 && debug.dev_menu) {
                 player_add_xp(game.player, 1000);
-                fighter_invulnerability(game.player, fix(999.0));
+                // fighter_invulnerability(game.player, fix(999.0));
                 player_f->skills[1] = AOE_SHOCK;
                 player_f->skills[2] = AOE_JUDGEMENT;
                 player_f->skills[3] = SKILL_DASH;
diff --git a/src/render.c b/src/render.c
index 5cbed1e..4182b88 100644
--- a/src/render.c
+++ b/src/render.c
@@ -279,7 +279,7 @@ static void render_entities(game_t const *g, camera_t const *camera,
             anim_frame_render(scr.x, elevated_y, v->anim.frame);
         }
         /* Show entity hitbox in the map coordinate system */
-        if(v && (!v->anim.frame || show_hitboxes)) {
+        if(v && show_hitboxes) {
             rect r = p->hitbox;
             r = rect_scale(r, camera_ppu(camera));
             r = rect_translate(r, vec_i2f(scr));
diff --git a/src/skills.c b/src/skills.c
index b0aeff6..0827948 100644
--- a/src/skills.c
+++ b/src/skills.c
@@ -18,17 +18,19 @@ fixed_t skill_cooldown(int skill)
         return fix(3.0);
     else if(skill == AOE_BULLET)
         return fix(4.0);
+    else if(skill == AOE_FIRE_CHARGE)
+        return fix(3.0);
 
     return fix(0.0);
 }
 
-void skill_use(game_t *game, entity_t *e, int slot, vec2 dir)
+bool skill_use(game_t *game, entity_t *e, int slot, vec2 dir)
 {
     fighter_t *f = getcomp(e, fighter);
     int skill = f->skills[slot];
 
     if(skill < 0 || f->actions_cooldown[slot] > 0)
-        return;
+        return false;
     f->actions_cooldown[slot] = skill_cooldown(skill);
 
     if(skill == SKILL_DASH) {
@@ -36,7 +38,7 @@ void skill_use(game_t *game, entity_t *e, int slot, vec2 dir)
     }
     else if(skill == AOE_PROJECTILE) {
         if(f->current_attack)
-            return;
+            return false;
         entity_t *aoe = aoe_make_attack(AOE_PROJECTILE, e, dir);
         game_add_entity(game, aoe);
 
@@ -47,7 +49,7 @@ void skill_use(game_t *game, entity_t *e, int slot, vec2 dir)
     }
     else if(skill == AOE_SHOCK) {
         if(f->current_attack)
-            return;
+            return false;
         entity_t *aoe = aoe_make_attack(AOE_SHOCK, e, dir);
         game_add_entity(game, aoe);
 
@@ -63,7 +65,7 @@ void skill_use(game_t *game, entity_t *e, int slot, vec2 dir)
     }
     else if(skill == AOE_JUDGEMENT) {
         if(f->current_attack)
-            return;
+            return false;
         entity_t *aoe = aoe_make_attack(AOE_JUDGEMENT, e, dir);
         game_add_entity(game, aoe);
 
@@ -76,7 +78,7 @@ void skill_use(game_t *game, entity_t *e, int slot, vec2 dir)
     }
     else if(skill == AOE_BULLET) {
         if(f->current_attack)
-            return;
+            return false;
         entity_t *aoe = aoe_make_attack(AOE_BULLET, e, dir);
         game_add_entity(game, aoe);
 
@@ -85,6 +87,21 @@ void skill_use(game_t *game, entity_t *e, int slot, vec2 dir)
         else
             visible_set_anim(e, f->enemy->id->anim_attack, 2);
     }
+    else if(skill == AOE_FIRE_CHARGE
+        /* || skill == AOE_WATER_CHARGE */) {
+        if(f->current_attack)
+            return false;
+        entity_t *aoe = aoe_make_attack(skill, e, dir);
+        game_add_entity(game, aoe);
+
+        f->current_attack = aoe;
+        f->attack_follows_movement = true;
+
+        /* This skill is used by enemies, the AI will set the animation
+           themselves on a per-enemy basis */
+    }
+
+    return true;
 }
 
 void skill_render(int x, int y, int skill, int bg, int color)
diff --git a/src/skills.h b/src/skills.h
index 8ee94e0..abc575b 100644
--- a/src/skills.h
+++ b/src/skills.h
@@ -15,13 +15,14 @@ enum {
     // AOE_SHOCK,
     // AOE_JUDGEMENT,
     // AOE_BULLET,
+    // AOE_FIRE_CHARGE,
 };
 
 /* Fixed cooldown for a skill */
 fixed_t skill_cooldown(int skill);
 
-/* Have [e] use its skill in the specified slot. */
-void skill_use(game_t *g, entity_t *e, int slot, vec2 dir);
+/* Have [e] use its skill in the specified slot. Returns true on success. */
+bool skill_use(game_t *g, entity_t *e, int slot, vec2 dir);
 
 /* Render a skill's image */
 void skill_render(int x, int y, int skill, int bg, int color);