Note I personally don't use this, and I know one person who does to great effect.

Step One: Hit something with "Solidify Water" (ARPG 428) with the last adaptation, Rendering a Target Helpless (until they take damage)

Step Two: Someone else hits the Helpless(ARPG 318) Target ( Av 11) and reduces them to 0 Stamina.

Done.

I think this might be a bit too powerful, I think the simplest way to keep the spirit of the original spell and not make it so broken, would be to change the adaptation to indicate that it breaks the hold on any attack allowing them to defend normally.

Thoughts?

The adaptation makes it CTN 24 (roughly a tier 3 spell) and the adaptation implies it changes to single target (though it is not explicit). How does the power level of this spell as written compare to other spells/adaptations/combinations around CTN 24?

If it is not noticeably more powerful than other spells with similar CTN, it should be left as-is.

If it is over-powered, then it should be errata'd in some fashion. However, I don't think I like your suggested fix (though I don't currently have one I like better).

Straight up there is no spell that makes people Helpless and vulnerable, Bury a Tier 4 spell renders them helpless, but essentially puts people out of reach pf attacks, censure heretic is T3 but only renders them helpless for 1d4 ticks.

I think the original intent of the (adapted) spell was to act similarly to a hold person spell

Perhaps it renders them "Immobilized" and "Stunned" instead of Helpless would help?

An 8 for your casting stat (passive 16). 3-4 ranks at creation (pass 19-20). Raise it three ranks in Tier 1 (passive 22-23). Three more ranks at Tier 2 (pass 25-26). Also at Tier 2 the possibility of a bump through a path and/or Sabaticle (pass 27-28).

CTN 24 is very much a something you auto cast sometime in Tier 2. Even a casting stat of 6 plus three ranks at start and a bare 3 ranks advancement at T1 & T2 will get you to 24.

Yes the spell is probably overpowered related to other options. Not sure what the best option is to "fix it."

I guess I'll write it into a mod to get my point across.... (he said, only half serious)

It does seem like it is very like overpowered and needs to be errata'd. However, I don't know what a good fix would be. Possibly Josh's original idea. Immobilize+Stun seems to go to far (target is free to do anything except move, free strike, or use a maneuver with recovery).

I honestly wasn't sure as I haven't really looked at spells over early tier 2 CTN (eg 20-22).

Increase the CTN to do this?

I'd like to see the insta-kill portion of the spell removed (the helpless condition)

The intent was to be a "hold person". However, people seem to want to 1 shot the Sorcerer King or something.
Just remember that what is good for the goose...