Chromium [Legends] Core Set 2020 Prerelease Promos the player can activate mana

the player can activate mana abilities only if they're from lands that player controls and only if mana they produce is spent to activate other mana abilities of lands the player controls and/or to play that card

When Leyline Binding enters the battlefield

as if it had always known

Set: Secret Lair Drop Series Type: Enchantment Rarity: Rare Cost: {G} Whenever an opponent plays a land

Chromium [Legends] Core Set 2020 Prerelease Promos the player can activate manaSet: Legends Type: Legendary Creature Elder Dragon Rarity: Rare Cost: {2}{W}{W}{U}{U}{B}{B} Flying Rampage 2 (Whenever this creature becomes blocked, it gets +2 +2 until end of turn for each creature blocking it beyond the first.) At the beginning of your upkeep, sacrifice Chromium unless you pay {W}{U}{B}.