Since beta got lots of stuff, including the hard limit of double casts, how about reworking Wizard king's signature ability?
Why? Because it can't work with ascension perk and weavers unit.
With what? Well, here is the idea.
Delete overchannel. Instead, give the Wizard king a new ability, that allows him to use any magic ability for free. By clicking on it, WK gets 5 magic tree abilities (chain lightning, freeze blast and so on). WK will be able to use that ability for free.
Casting that ability costs 0 AP.
WK can use the same ability twice, if they have it learned by then. Like double chaind lightning
CD 1 turn.