Sovereign of New Asgard

Keep a Quincarrier on hand to play Death Glow without sacrificing cards in hand. Use Build Support to find it sooner.

Superpower Training targets Valk's necessary hero-specific upgrades to boost her stats; though not as cost effective, first one of her weapons then Aragorn.

Cameo Lady Sif from the Thor hero pack for an additional Asgard ally in Leadership. Hopefully Thor is already in play in order to get maximum benefit.

Asgard allies are expensive. Recruitment Drive lets you spread the cost out over multiple turns. Build Support can bring one into play in hero form. Avengers Compound holds an ally until the resources are at hand. Resource Reserve holds a resource card, especially Organizational Support. More use is made of Valhalla and The Bifrost which can be tapped to boost Organizational Support. Call for Backup brings an ally in immediately.

Since these allies are so costly, Team Training gives them all +1 hit point. Rapid Response them back to the field of battle. Or at least get card draw from their defeat with Avenge Me. Or both!