I've tried every Musharna variant in existence, other than maybe some gimmick sets I don't know about. First of all, she really wished she had 5 moveslots, as decision between coverage move and Heal Bell is big.
Signal Beam might take Absol, sure. But Skuntank will bash your face in.
Life Orb variant seems like the best compromise, however even with max SpA investment it misses out quite a lot of OHKOs, unless you pair it with Modest nature which in turn hurts your bulk. And that can bite you in the ass. I've finally settled on:
Musharna @ Life Orb
EVs: 240 HP / 16 Spd / 252 Def
- Heal Bell
- Hidden Power [Ground]
I am however still tweaking.