so neutral IVs DC/QR FCorrin with Bonfire, Dark Breath (+Res), Distant Defense seal, and buffed with Fortify Dragons both tanks and counter kills Brave Lyn (both Brave Bows and Mulagir) and Reinhardt that are optimally offensive (+atk ivs, death blow, hone calvary). Like, wow. I'm working on this right now and I'm super excited for it, grinding out the sp. I know the battle sim isn't very reliable since it only factors in default builds, but it says this build dies only to Julia and Deirdre. FCorrin is a tank goddess. And this is without factoring in ally support holy hell.
Since Elise/healers are now a thing I've been wanting a tank and now I can have a sisters duo thing going on yays.