Interesting. I switched in a Horus with Bespoke and Ygg, and I'm seeing VanHelsing die in the first round too. I assumed it was somehow to do with Ygg putting on golden hit, but maybe it's Horus's bespoke? I looked at the bespoke and I don't see what's doing it.
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I don't see how the bespoke could do anything, but maybe Horus's MA passive is doing it.
"Enemies take random damage whenever they heal, based on the amount healed, until they die every turn."
Van Helsing's passive is healing him, so maybe this has something to do with it. But it's still related to the marks, because I didn't kill him in the first round when I had a stronger Eddie in place. Only with Scream for Me.