Terra Branford (Urza, Lord High Artificer) Artifacts are Magics strongest card type, so it should be no surprise that an artifact commander would be one of blues best
Plenty of strategies can exploit replay land effects
in cEDH, Blood Pet is often found in Krrik, Son of Yawgmoth builds as a way to net an extra mana for 2 life, but also sees a lot of play in Inalla, Archmage Ritualist and Ad Nauseam lines to rush out these expensive spells or aid in comboing off with other cards to win the game
Past in Flames gives instant and sorcery card in your graveyard flashback, which can be an unpleasant surprise for your opponents
It's not the easiest thing in the world to turn this buff on, but this is a nicely-statted creature that can hate on graveyards in a format where that matters
Her -6 effect probably doesn't come up often, but it would be pretty handy if all your Talents and Forges ended up in the graveyard