It didnt last too long in Legacy before getting slapped with a ban
While it takes a lot of green mana, it's possible that you can cast Nature's Rhythm to tutor out a combo piece and then tap that combo piece to help pay the harmonize costs on Nature's Rhythm to snag your second combo piece and win the game
Nexus of Fate One of many extra turn spells that broke Magic, Nexus of Fate was especially hard to swallow because it was supposed to be a just-for-funsie promo
Dauntless Escort Selesnya decks need all the protection they can muster in Commander since everybody plays board wipes and this color combination is particularly susceptible to them, so you can justify Dauntless Escort in more than a few decks when you need to keep the creature count high
The two most well-known cEDH decks in recent memory that heavily featured Rule of Law effects are Winota, Joiner of Forces and Tayam, Luminous Enigma
The synergy with Ultron, who can copy every artifact card you cast as a 2/2 robot, appears to be the main reason this price spike has occurred, that combined with the low availability of foil Doctor Who cards