So do undead Tev and living Tev exist in the same world somehow? And is Tev still flirty?

No, paladin!Tev is usually in an AU where he survived Scourgeprom. They don’t exist in the world together, even when I do stuff like this:

Tev Tev isn’t normally flirty, and only gets flirty when he’s extremely drunk. (So basically you need to give him hard liquor spiked with lichbloom or something.)