Immolation Based Ablities

I want to make a hero with three abilities that are activable/deactivable. ONLY ONE of them can be activated at a time. When hero activates one of them it drains mana (just like the immolation without the burn damage). My question is: There are 2 immolation abilities in the game... how can i make 3 based of these without messing the things up when i activate ONE them?

Base it off defend, and trigger it. Alternatively, you could try putting it into a spell book if you don't mind that.

This is an alternative but i want it ONLY to spend mana. Also i need 3 of theese abilities... Any other suggestion?

You can't base 3 abilities off 2 base and have them work properly.

You could just trigger the entire thing with a dummy ability for on/off for each ability. So 6 abilities, one on and on off per ability.

There's the Demon Hunter's Immolation ability... what's the second draining ability? Nothing's coming to mind at the moment.

isnt there also a neutral immo that isnt perm? the dh's and just units?

If there is another draining Immolation, it's not a unique ability. The two won't both exist correctly on one unit.