I’ve tried this famous Physical one by AlkamosHater at one point (but generated quickly with random rolls by gd-edit) and also my own Vitality one and both felt terrible against Ravager for some reason, like I would need to fight 5 or maybe 10 minutes even? And AlkamosHater beat it in just over a minute. I couldn’t even tank (but even with tank it would have been super long). Physical maybe because of (converted) Physical damage changes or some mistake of my own, I’m not sure. Vit maybe because it was Vit Death Knight and meme 
Acid has all these conversions available, doesn’t need to fight with armor so maybe it’s the best candidate now for Retal DE? I don’t know. The added 5m target Area from both of Retal DE items might be fun to use. 20% Retal added is like 2000 flat damage (before % Retal) in this build so it should be good?
Good catch. And I would like OA to be a bit higher. I kinda need them for overcaps atm though so maybe I’ll try to include them if the character is tanky enough.
Actually the Cold → Acid conversion doesn’t matter that much because all RR in the build (Vulnerability, Spectral Wrath, Murmur and Mark of Dreeg component) contains Cold RR and % Cold Retal is only slightly lower than % Acid Retal. Another non-intuitive thing that sometimes happen with Retal.
Sorry for not testing and just GT, I’m kinda in between computers and only have some old temporary laptop atm.