Why not give Blitzcrank a heat system similiar to Rumble's?
I mean a steam golem that runs on electiricy while using mana? Talk about weird. There would have to be some changes to his kit tho, but I can see this working. His ult could become a skill called "Steam Discharge" that consumes almost all heat and deals more damage the more heat is consumed...
We gotta have to change how his Q works then, because without mana to gate it it's a little too op early...
(core) + tankyness:
or
.