+Def -HP Bridal Tharja

You could try using her with an alternate build.You got lucky that it wasn't a valuable stat that was decreased, so you just run her with Fury and Desperation, or whatever suits your playstyle.

I guess any build, really.

Her default tome gives her an extra 3 speed and gives her an Owl-tome like effect (for allies within 2 spaces) for attack and speed. She has a bond skill that increases her attack and speed as well.

Mine is +Def -Spd... I just did a vanilla build 49/35 is still decent, and her tome and Bond brings her up to 60/46.