There are four builds I recommend on Karla: desperation moonbow, desperation galeforce, shield pulse, and AoE special. The choice of A-skill depends on the build. AoE special is the only one where I recommend wrath; it's just so hard to take multiple counterattacks.
I got the same and went mad with Life and Death, 52 Atk and 49 Spd before buffs. She really needs to run Desperation thought with such tiny defences. Death Blow's probably safer as she doesn't really need that much unbuffed.
If you're in top 10k arena assault, she can put in a lot of work. If higher, you'll run into merged units and she won't cut it, so you should fodder wrath to your other merged or built up units.
This is mine, also -atk +spd.
(Since she is +5, subtract 2 to every stat for her unmerged stats)
Edit (translation): Vassal blade, reposition, glimmer, LnD, desperation, odd speed wave, atk+3 seal.
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