We think the header pretty much covers it, but just in case, let us elaborate: until the April game update, you'll be able to earn quest progress when challenging your friends in MTG Arena
The highlight cards are Arceus EX from Triumphant Light and Dialga EX from Space-Time Smackdown
Krenko makes an insane amount of creatures over the course of a game, and having an indestructible second commander that shoots damage and is able to give firebreathing to your entire board seems like its going to shoot out a lot of damage
She also has earthbending, which lets her transform lands into creatures with haste, and put counters on them
Boseiju, Who Shelters All For Boseiju, Who Shelters All to be worth the 2-life tax it imposes, you need to be casting big instants or sorceries that win the game if they resolve
I do not recommend doing so