Does Threshs bonus ability power form Souls get increased by Rabadons Deathcap?

The wiki states that the armor is affected by % increase effects (the mastery), so I'd assume the AP applies the same way.

the best way to figure it out is try a custom game and see what happens when you build rdc.

Rabadon's Deathcap increases your flat AP by a % amount, so yes it does increase the amount you get from Souls.

For it to be noticeable you'd just have to have quite a few souls.

yes it will but when you check ap from souls it wont increase but your ap from the passive of deathcap will

tys