There is a downside to these, of course, as they each cost four energy and lose two energy per attack
While you wouldnt want to play either one willingly in most cases, there are times and places where you just desperately need an Omega Myr in your Mirrodin Limited deck to keep from being run over by the Nim Draft archetype
When Theros was out, I was a huge fan of the Devotion mechanic because of how it supported mono-color decks in a Magic world where duel-color or tri-color decks feel like they're the supreme
Best wishes on your quest
If you're interested in how these will play in Limited formats, check our Modern Horizons 3 Limited Set Review where we rate all the cards, and our MH3 Sealed Guide if you're specifically interested in Sealed or our MH3 Draft guide for, well, Draft
While generally very strong the card doesn't translate that power across to this archetype nearly as well as you might expect