When both of these cards are on the battlefield, Urborg, Tomb of Yawgmoths ability gets overwritten by Blood Moon turning it into a Mountain
But at the end of the day there were some serious misses in this precon, and with as many reprints as the deck had, it seems silly that it had such huge misses, with BitterblossomBitterblossom and fan favorite Faerie MastermindFaerie Mastermind not making the cut
Otherwise, its strong, but not broken
And since its a Trap, you can do this on your opponents turn to summon some negation they didnt count on
Brawl Legal Vintage Legal Timeless Legal Commander Legal Pauper Not Legal Oathbreaker Legal Penny Legal Toolbox Notes and Rules Information for King of the Oathbreakers: If a spell an opponent controls targets multiple Spirits you control, King of the Oathbreakers's triggered ability will trigger once for each of those Spirits