Raven + Special Spiral

Sothe is a decent option. He has a very similar statline to Ophelia's. The disadvantage is that he hits def, and a lot of armours get their def into the 40s if not higher. Strong res is a bit less common except in AR where mages are popular so most tanks need res.

Raven I don't think is good with a spiral build. Due to his inability to take more than one hit, you would be building him as a OHKO machine when he has well over 40 points in spd which would become irrelevant.

I'd say that OHKO units in general are those that benefit most from special spiral. They were always unsure what B-skill to use, and OHKOs tend to be shaky because you're competing with the opponent stat point for stat point whereas attackers who depend on doubles get 2 damage out of 1 point of atk and can potentially use their specials for even more damage.

But if you're not sure, I think it doesn't hurt to wait 2 weeks, let IS show us how they designed beast units as far as game mechanics, and then decide what you want to do with your spiral.

Even with bad IVs Lewyn is a pretty respectable mage using his base kit until you decide to fodder. I keep two different IVs around: +atk -spd, and +HP -def (which is virtually neutral, but back when I used him in AR, having 41HP was really useful for being resistant to tactics rooms, gravity traps, and panic manors)