What about Dannato (Harm Spell Vendor)?

[Lanhelin]

So the wiki says this about purchasing the Harm spell. I talked to Verisgante in undead form, having the item in inventory - there's no dialogue option to summon Dannato. What is the trick to get him summoned? Or is this just a prank?

Edit: Additionally the tooltip of Heal says that it acts like Harm on undead - but it doesn't, I'm always immune to it in undead form. But shouldn't it hjeal meh?

[MartinusWyllt]

...What is the trick to get him summoned? Or is this just a prank?...

He got lost when the collectible vendors turned into augment vendors. Apparently there's talk about "doing something" about that, that's the last official response I've read on the matter.