Arena of the Ancients [Legends] Premodern any time you could activate

any time you could activate a mana ability

Set: Antiquities Type: Artifact Creature — Shapeshifter Rarity: Rare Cost: {6} {0}: Urza's Avenger gets -1/-1 and gains your choice of banding

Set: Promo Finish: Cold Foil Type: Action Subtype: Item Rarity: Promo Class: Generic Cost: 0 Action - Destroy Timesnap Potion: Gain 2 action points

If you have 13 or less [Life]

It's found in the silence that follows

Arena of the Ancients [Legends] Premodern any time you could activateSet: Legends Type: Artifact Rarity: Rare Cost: {3} Legendary creatures don't untap during their controllers' untap steps. When Arena of the Ancients enters the battlefield, tap all legendary creatures.