HolyCarp
[14] Master
Problem with 4B (and 66K) is that if the opponent isn't ducking, they'll likely go for JG~G or sidestep (if their frames allow it), so each time you use 4B against an active defense, you risk getting launched in exchange for 20 dmg. While they do add up, it's so easy to guess wrong on, let's say, the 4th mind game and take as much damage as you dealt with the previous 4B chain. I mean, there's 4K if you're scared of JG, but even still it's not much guaranteed damage. Not like Ivy's iFC 1B for 101 dmg (1 bar) + amazing oki.4B adds up pretty quickly since it's so easy to land multiple in a row. Asta's CE also gives him big damage against -17 or worse stuff where he'd otherwise only get 66B or a throw attempt. I think it's also harder (impossible at most ranges?) to backstep Asta's CE after getting hit by 4B or 4K than it is to backstep Ivy's CE after 3K or 3A (possible at most ranges?).
Definitely agree about the range though. I believe he also has more active frames, making it a more reliable punisher (TC recovery always felt like more of a problem for Ivy's CE in my experience).