Mist of Stagnation does not prevent Wrenn and Realmbreaker's passive ability

Machine
Machine Posts: 871 Critical Contributor

I was paired against Wrenn and Realmbreaker during the last team event (Rise of the Adventure), so I boarded in Mist of Stagnation. It prevented his Ghalta to convert gems to green, but it did not prevent Wrenn's passive ability to convert gems. The card reads that it prevents conversion effects of planeswalkers and spells.