Halloween Myrrh Build help

Here's some ideas that come to mind:

If you want her to be able to tank, and also have her be able to use DC, you could try giving her a refines Lightning Breath+ so she gets +5 more HP and a stat of your choice, at the cost of an amazing BF-like weapon. Wary Fighter helps her negate doubles but also prevents her from doubling. Brazen Atk/Def 3 helps her tank more and deal more damage once she reaches the HP threshold. Or you could also substitute it for a stance skill. For seals, DD or CD depending on which side you'd like her to tank more.

Edit: Misread the post, so you can ignore a good chunk of this.

If you don't have the DC fodder, then the next best thing might be to run one of the Breath A slot skills. Since H.Myrrh already brings a lot of natural bulk, you might want to try Warding Breath to maximize on her Res (Although you'd probably be better off running Steady Breath). The Brazen skills are also viable and unorthodox options. I'd say that H.Myrrh's base kit is pretty solid however so, unless you really wanted the built in DC with Lightning Breath, I'd say you're good to go. And if you can afford it, Aether is a great armor/dragon special especially when equipped with the cooldown of one of the Breath skills. But if you don't want to deal with the cost of Aether, the damage based specials are very helpful (Bonfire, Ignis, etc.)

Honestly, I think Sturdy Blow is the best slot a on her. It synergizes with Spirit Breath and increases her offensive power. Vengeful fighter is enough for enemy phase so focusing on her player phase more is where I see room for improvement. It’s also very available since you can get it off Athena.