Zilean Bombs on targets should grant assists + tower kills

I used my Timebomb on someone that was at an incredible low health. It resulted in my death, but i was ok with the trade as it was shutdown.

They just ran into the tower and got executed. I dont think that should be how it should work.

Edit : i also think his mana costs are a bit high, ult should be lowered quite a bit considering it's his "high moment"