Seething Song [Mirrodin] Planechase Scion of the Ur-Dragon becomes

Scion of the Ur-Dragon becomes a copy of that card until end of turn

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

Put Seasons Past on the bottom of its owner's library

Set: Commander 2016 Type: Enchantment Rare Cost: {1}{B} Whenever an opponent discards a creature card

Set: Modern Masters 2015 Type: Legendary Creature — Eldrazi Mythic Cost: {10} When you cast this spell

Seething Song [Mirrodin] Planechase Scion of the Ur-Dragon becomesSet: Mirrodin Type: Instant Common Cost: {2}{R} Add {R}{R}{R}{R}{R}. Vulshok mana rituals echo the day when the red sun burst through Mirrodin's surface to take its place in the heavens.