Blighted Summoning and spellpower

[EatThisShoe]

So I've got a summoner doing nicely on Nightmare, and I was thinking about getting Blighted Summoning, except it occurred to me that all my summons have only 1 spellpower. Does Blighted Summoning grant any spellpower that isn't mentioned? Are the spells any good without spellpower? I assume they are at least at 5/5 talent level. Also since I'm a Yeek, does anyone know if the Mindslayer summons who use Dark Portal will end up catching me in their portals, or are they smart enough to avoid friendly fire?

[sehnsucht]

Forget it. Hydra's blood spray does only 160 damage at 70 spellpower.

This prodigy sucks for summoners

[HousePet]

Your Mag is added to your summons stats when you have this prodigy.

Unfortunately they are given the talent at level 3 at the moment.

[Sirrocco]

Who is it good for? My understanding is that Doomed could potentially work well (their shadows already need magic to do their thing) but the AI doesn't know how to use it. Are the thalore/yeek versions any good? Alchemist? Solipsist? Oozemancer?

[HousePet]

Necromancer is the obvious choice for who it should be good for.
Anyone else with multiple summons can potentially get good results from it.