A 5-mana 4/5 with Trample isn't great, but it's not a disaster either, and if you can buff this at instant speed it can produce some blowouts
It also has a ton of win conditions that build up power passively, making it very difficult to stop once it gets going
Young Pyromancer is excellent, but I am hesitant to use it in decks with few creatures, as people play a fair bit of removal for it in Standard
Once youre in on the Rat Colony/Relentless Rats plan, one of the most powerful cards in your deck is Thrumming Stone
Despite an impressive start to this new Moonbreon's TCG career, it quickly lost value, dropping out of the $300 range after starting above $350
Activate only if a player has one or fewer cards in hand and only as a sorcery