52 Spell Penetration works on basically every Elite quest and Hard raids. I think for Legendary Elite raids this is not the CC build you will be looking for, it lacks few more Spell Penetration and Enchatment DC, altho you could make it work with a few changes.
I tried Burst of Glacial Wrath and I love it, DC is a bit low tho. Anyway Greater Ruin > BoGW sadly. I'd love to use it but I'm just going with this OP spell for now, just like Arcane Pulse.
Also, just Duoed Thunder Peaks with Rys. Amazing fun run!