Tharja Winter Build

Well.....the reason she feels underwhelming is bec she gets most of her power from special procs (ignis/glacies). And aether doesnt really get reliable kos, so........

You should stick to her unmovable sovereign recommended build with candelabra refined for res/def. If you want consistency that is. If you have aether for arena points then theres little you can do without changing her weapon /set entirely

Pretty much how I run mine, except I use defense/resistance refines on her weapon and close/DD seals. I like your idea; a ward armor team makes her super tanky even if she isn't running def/res refines or defense seals, so that lets you boost her attack (which she kind of needs, in my opinion, since mine has trouble killing things at times).

Great build man. You might giver her def/res refines so you have that option if you never need extra points in those stats, but other than that, I've got nothin'.

I have the same build on a +Atk/-Res, and also use her in a Ward Armor team. I haven't pulled the trigger on it yet, but I have had my eye on giving her Death Blow 3 + Bold Fighter.

Obviously it completely changes her from being an enemy phase unit into a player phase unit, so I was thinking about ditching Ward Armor in favor for x3 Armor March + 1 Panic Ploy, and switching out my defensive BK in favor of Bold Fighter Zelgius so everyone can get around easier + being more aggressive.

I run my +HP -Spd (best I could get) with Rauðrblade+, Aether, Close Counter, Vengeful Fighter and Armor March and she's pretty dam hard to kill having carried me on several Rival Domain/Grand Conquest battles. She usually just has VA!Hector with Fortify Armor in that situation and with the blade and Aether she does good damage and healing. With a defensive tile she survived and killed a Death Blow Reinhardt. The set wouldn't be so useful on your Ward Armor team but switching 1 Ward to a Fortify would be enough.