Few Modding Questions.

Is it possible making one unit available for construction in a specific tileset only. or just change the skin for that unit in a specific tileset ? i know its in the TFT editor but i believe it only concerns the placement inside the editor.

also how can i give a unit a spell with one charge ?
like give a footman a water-elemental but it wont cost mana and once you use it its gone. kinda like Huntress's Owl but a different spell.

make a custom spell
then make a trigger whenever that spell is cast, remove it from the casting unit