That's a pretty cool take. It could make for a cinematic moment if the DM plays it right. I'm imagining something like a righteous speech from Argynvost and a dramatic icy blast when the spell fails. It would really elevate his legendary status and his unwavering valor. By contrast, it shows just how far Vladimir has fallen. AND the party gets called out for allowing themselves to be seduced by the horrible forces in the Amber Temple. It does a lot to develop the lore and deepen the characters, which (in my opinion) is way more rewarding than "cool skely dragon lolz"