mtg cards like bitterblossom Custom Proxy At the beginning of your upkeep Bitterblossom - MTG Proxy Modern

Another key characteristic of hybrid mana cards is that they count as all the colors or mana in their respective costs , both for MTG rules and for Commander color identity

Apparently not Wizards of the Coast, at least, not anymore

Partner (You can have two commanders if both have partner.) Illustrated by Svetlin Velinov Standard Not Legal Alchemy Not Legal Pioneer Not Legal Historic Not Legal Modern Not Legal Brawl Not Legal Legacy Legal Comp

Meanwhile, it takes a ton of level counters to make Transcendent Master powerful, but if we get it all the way to level 12, it is an almost unbeatable (outside of exile-based removal like Path to Exile) threat