Ayra A slot

Ayra and Karla are two different creatures, and there's a critical difference that the GamePress article missed. Ayra's def is considerably better than Karla's which enables her to take an extra hit or two, which means she can use wrath relatively easily whereas Karla will not have an easy time using wrath because she tends to collapse on the counterattack. What this allows Ayra to do is take the slaying edge and hit her opponent with Regnal Astra twice (unless they use guard, in which case they only take one), which I guess Karla can maybe try to replicate with brazen atk/def and moonbow? It wouldn't be easy to pull off without +spd, and even with, survival might be an issue. So I find that Ayra actually has a higher damage ceiling than Karla, and I recommend that she simply seek to sit on that as her niche and let Karla struggle with bulk and, for example, pick up desperation galeforce, because she has a good weapon for that.

All of that to say, I think Ayra is best to accept that she doesn't hit very hard without her special. You don't need to do funny stuff because you're scared of people using guard. Use the slaying edge build, use quickened pulse or infantry pulse her to guarantee at least one RA.

The best Ayra build (or at least the most terrifying) I've seen was specialized for arena defense. It was Slaying Edge+, Regnal Astra, Distant Counter, Wrath and Quickened Pulse. The basic idea of it is that she will take a single hit, (the Regnal Astra is available from the start due to Slaying and QP, so it can be used on either enemy or player phase) and hits back with a +10 damage (because she's most likely under 75% HP from that hit, so Wrath gives the extra damage) Regnal Astra. At base, that's an extra +16 damage from the special proc, not including Wrath. Plus, she most likely has the speed to hit you again and the bulk to not quite be one-shotted.