While the obvious first home for Urza's Cave is Tron decks as a failsafe for games where it's difficult to assemble the three Urza lands necessary for the strategy's explosive mana acceleration , it's also interesting to consider what else Urza's Cave can do in decks featuring Knight of the Reliquary, Elvish Reclaimer, and the Modern Horizons 3 reprint Sylvan Safekeeper
While Renata will easily fall to damage if not appropriately protected, I think the rewards will outweigh that risk
Promo Info BOOSTER X RECORD [BT-09] CLOSECLOSE BT9-005 U Digi-Egg Lv.2 Parallel Rare Tumblemon Color Black Form In-Training Attribute - Type Rock DP - Cost - Digivolve Cost 1 - Digivolve Cost 2 - Upper Text - Lower Text [Opponent's Turn] While this Digimon has Blocker, it gets +1000 DP
Delta Species Rayquaza from the Dragon Frontiers set turns Hoenns third legendary into an Electric-type
For 5 total mana divided across turns, you can steal opposing cards and pay mana to play them later, which can be beneficial in the grindy match-ups