Well to be perfectly honest, this spell does not do anything different than any other out of the ton of spells that are released on OTLand as well as in RL Tibia. A fancy (even if that) effect does not make a spell good.
I don't know what kind of an OT you are developing, but I'd recommend you to try something new, implement some mechanics for the spell, make something unique as in:
"[Spill Gasoline]
Cooldown: 1 second
Mana cost: 20
Deals low damage on a tile in front of you and spills a pool of gasoline onto the tile."
+
"[Flame Engulfment]
Cooldown: 20 seconds
Mana cost: 165~
Your character explodes with flames, dealing damage to all surrounding units. If the flames hit a tile that has gasoline on it, the tile will produce an extra explosion dealing more damage to all units in a 3x3 around it."