Vanishing 2 (This permanent enters with two time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.) {T}: Add {C}. When Unstable Footing is put into your graveyard from the battlefield, if it had no time counters on it, search your library for a basic land card, put it onto the battlefield, then shuffle.
Vanishing 5 (This creature enters with five time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.) {1}{R}, Remove a time counter from Unstable Magmaling: Flip a coin. If you win the flip, it deals 3 damage to any target.
Whenever Unstable Vein enters or leaves the battlefield, choose one — • Put a +1/+1 counter on each of up to two target creatures. • Unstable Vein deals 2 damage to target creature with flying.
Slyten disintegrates, into the air you breath and also in the water.
Unstoppable Slaughter deals 1 damage to each creature and each player. Whenever a creature dealt damage by Unstoppable Slaughter this turn dies this turn, repeat that process.
Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.) Unstoppable Weed gets +1/+1 for each +1/+1 counter on other creatures you control.
Trample Whenever Unstoppable Zealot deals damage to a player or noncreature permanent, you may put a land card from your hand or graveyard onto the battlefield.
Choose one, then choose another for each card named Unsuspecting in your graveyard. • You may return a permanent you control to its owner's hand. • You may put an artifact, creature, or land card with mana value 2 or less from your hand onto the battlefield. • Untap up to three target permanents. • You gain 4 life.
Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.) Whenever a creature you control becomes renowned, create a 1/1 red Soldier creature token with haste.
Whenever you cast a nongreen spell, creatures you control get +1/+1 until end of turn. Wanderlust — When Untethered Disciple enters, if you control four or more differently named lands, create two 1/1 Scout creature tokens that are all colors.
{T}: Add {C}. {T}, Sacrifice Untethered Spire: Choose target land card in your graveyard that was put there from the battlefield this turn. Return that card to your hand.
When Unwavering Sentinel enters, for each creature you control, create a white Aura enchantment token named Shield with “Enchant creature” and “If enchanted creature would be destroyed, instead remove all damage from it and sacrifice this Aura” attached to that creature.
Unzari Ruins enters tapped. {T}: Add {C}. Tap five untapped creatures you control: Unzari Ruins becomes a 10/10 Construct artifact creature with trample until end of turn. It's still a land.
If you would create a token, you may instead create a tapped 2/2 green Faerie Bard creature token. Whenever one or more creature tokens you control deal combat damage to a player, that player sacrifices an artifact or enchantment.