Conditional spell known, and taking damage on activation

[Brolthemighty]

Alright, so I'm working on an Epic Boon currently that does multiple things. Some of it, I've already figured out...and some of it's being tricky. It breaks down thus:

- On activation, player reduces maximum hp by total level
- On activation, player's Eldritch Blast cantrip turns into Hellfire Blast
- On deactivation, player's max hp returns to normal, but no healing takes place (leaving current hp where it was)

I have the max hp thing using an Eval:
Post/10000

~ If we're not shown, just get out now
doneif (tagis[Helper.ShowSpec] = 0)
doneif (tagis[Helper.Disable] <> 0)

if (field[abilActive].value <> 0) then

~Reduce our HP
herofield[tHP].value -= #totallevelcount[]
endif

I've bootstrapped the spell, but can't get it where it only appears when activated. I even had to add fields to make it show as a Racial Spell to make it show at all....which I can't figure out why. Any help? I can't find any way to finish this up. Is there a way to make the spell (Hellfire Blast) replace Eldritch Blast in their list on activation? Right now I'm just opting to add it to their list of cantrips available.