The drawback is actually an advantage alongside a Mentor-type effect since it'll keep triggering it.
That is situational though. If you cast Karak, go to case a spell, they bolt Karak in response and you lose the flip you really just got killed on tempo. Him getting bolted out is always a threat but with the few of these cards all that will happen in the worse case scenario is Storm count+1.
I think the interaction with Mindbreak trap and MM is actually really strong and you would likely want to use them over any traditional counter magic, and I could see a list that wanted to run bolts and somelight disruption and just go face. Pyromancer seems fine, I think Mentor and splashing white at that point seems win more since you cannot protect it with FOW as you normally would be able to.
Not sure what other purely free spells there are that are worth exploring. Mogg Salvage could be a thing.
All I know is that in a red/black storm shell, getting 2 Tutors and a few Rituals off should be an easy GG.
It CAN turn Manamorphose into a Darw 2 ritual. Not the hill I want to die on for this though.
This card is going to have some REALLLLLLY feel bad moments.
Losing to Krark's flip on your Flusterstorm seems like one of the better things you could do, I think I would start there. Also its worth mentioning that Ravenous Trap is unaffected assuming it's condition is met. Seems to me his largest downfalls are that you almost certainly won't be running the up-to-12 various Forces that are available and that he is miserable with a Sphere around, but those can be mitigated in deckbuilding. I'm assuming that anyone playing this card is accepting the addition of greater variance to a high-variance game and ignoring that argument.
Helping your opponent stock their graveyard is always a rather dubious strategy in Vintage, but wow, mill 26 for 0 is certainly efficient enough to deserve respect.
I am also a fan of this archive trap plan.