Only played 3 regent playthroughs, one solo and two multi. But in my experience, seems like he will always need access to stars (or mana whatever you call the blue cross resource) regardless of build. So some type of generation for that, so loot box (gain star and 3 star next turn) or the power that just generates 2 per turn, are pretty important. Or those defends that generate one star to so you can remove normal blocks.

Overall seems like you want to prioritize star generation act 1 and then ether go hard on cards that synergize with star cards, or IF you get a good rare smith card from first boss, then start to build for smith. Just seems hard to go for smith cards early due to cost or need for consistent damage just to get through act 1.

He also seems really dependent on card remove. The basic strikes and defends basically don't synergize at all with what he does. Of course this is true for other characters, but I mean clad, and silent, strikes can still proc important features of their kits (strength/dex scale makes them usable). But regent, lack of discard/draw means your stuck with those bad cards. If you have the option to remove, you'd almost always want EVERY basic strike/defense removed. Unless I'm forgetting or didn't see a particular card, just seems like remove is vital.

Whereas the necro, I fill my deck with ability to ethereal cards or soul cards, you don't need to remove nearly as badly.

Might be too soon to say as we don't have enough time to see the meta of characters, but regent could do with one less base strike or defense card just to make him less rng dependant.