Which Mathilda is better?
So Mathilda broke my pity rate at 4% with the best boon (spd)... But with the worst bane (atk). Which one should I keep, - def +res or - atk +spd? With the other one should I merge or inherit (or give her an atk +3 A slot)?
I agree, with the guy above me, on everything. The only exra two cents I have offer is if you actually like Mathilda then try waiting for a +Atk/-Def since her resistance is already great and her attack really needs the boost.
You could merge. CA is way too niche and you'd probably only use her for inheritance if you really want to give a unit Ridersbane.