Dettlaff Vampire Form

Dettlaff van der Eretein is the higher vampire at the heart of Blood and Wine. He’s the so-called Beast of Beauclair, behind the killings that bring Geralt to Toussaint. In the expansion’s climax his vampire form comes out in full: a winged, monstrous shape far beyond anything a lesser vampire can manage, and a fight that needs Regis’s help to win.

Geralt first faces him in his humanoid form when he tracks him to a warehouse. After the vampires overrun Beauclair in The Night of Long Fangs, everything leads to the final confrontation in Tesham Mutna at the Tesham Mutna ruins in the Caroberta Woods.

How that meeting plays out depends on your choices. If you went to see the Unseen Elder, Dettlaff shows up and leaves you no choice but to fight. If you brought Syanna, he tries to kill her. With the ribbon from the Little Flint Girl she is teleported to safety and an enraged Dettlaff attacks. Without it she dies, and you can either fight him or let him go. Beating him counts as a proof of valor for There Can Be Only One.

Combat strategy

The fight has three stages, and the game doesn’t save between them, so save while Regis keeps him busy and use that break for decoctions and repairs. Stage one is his humanoid form: he dashes in and dodges away after a hit, so short dodges behind him and quick strikes work best. Stage two is the flying form. Roll through his dashing slashes, and run as far as you can when he gathers bats, because the bat wave ignores Quen. Hit him hard when he lands. Stage three takes place in an illusion of his chest, where you destroy three pulsing hearts while fighting off hard-hitting blood clones.

Don’t count on oils. Vampire Oil, and any other oil, has no effect on him. Use the Griffin and Arachas decoctions for protection instead.
Keep Quen up, but not against the bat wave.
In stage two, knock him down with a well-timed Aard, Igni or crossbow bolt, then strike. Magic Trap works too.
Pure status bombs like Northern Wind do nothing. Grapeshot and Dancing Star work.
Axii doesn’t affect him. On high difficulty, don’t rely on Black Blood. Just avoid getting hit.
Blizzard makes stage three much easier.