FUCK DORA IN GREY.
Absolutely unfair. Her moveset 100% chance Beguilement, a high chance ability seal, 3 moves per turn, high agility, non elemental magic AoE (un-mitigatable), high damage single target physical, HP drain and also 100% critical physical attack. She can pep up. You need to stack all of your accessories to resist Beguile (which got me around 40% resist each because mastering them at the forge is not easy) and hope she doesn't get any procs off on the first turn. Also you need to hope she doesn't kill any of your team on the first turn and since she usually acts before you there's a good chance you've lost before you even get to make a move. Took me like ten tries, eventually managed it with Gublet (err… Hero? Luminary?) / Jade / Serena all pepped up going in, do the defence / attack buff Ult and then use Serena to use status immunity on everyone, starting with herself then Sylv, because he needs to acceleratle & multi heal pretty much constantly and until you get your 4th person buffed there's a good chance she will lock their abilities and mess up your run. Then hope a decelerate lands on her before she peps up and has the chance to do 6 actions in a row. Even after that it's still tough because you need to be dealing damage to prevent her HP drain healing her all the way back up, while managing Sylv and Serena's MP because if those run out you're fucked. So much RNG bullshit. That has been the only time so far I've considered turning hard mode off.