Laying out the necessary cards for comboing with Scion of the Ur-Dragon commander deck.
Combo: Infinite Mana To Direct Damage
Animate Dead + Niv-Mizzet, Dracogenius + Worldgorger Dragon
Infinite Mana Loop:
1. Animate Dead targeting Worldgorger Dragon.
2. Worldgorger Dragon enters the battlefield, triggering it's ability to exile all other permanents (including Animate Dead).
3. Exiling Animate Dead sacrifices Worldgorger Dragon.
4. Worldgorger Dragon goes to the graveyard, triggering the return of exiled cards.
5. When lands are returned, they are untapped.
6. (Repeat) Animate Dead returns, triggering ETB, targeting Worldgorger Dragon.
Use infinite mana to activate
Niv-Mizzet, Dracogenius
ability to do damage to target creatures or players.
Combo: Infect Damage
Moltensteel Dragon + Scion of the Ur-Dragon + Skithiryx, the Blight Dragon
1. Activate Ur-Dragon ability, targeting Skithiryx, the Blight Dragon.
2. Activate Ur-Dragon ability, targeting Moltensteel Dragon.
3. Let second ability resolve. Ur-Dragon is now Moltensteel Dragon.
4. Pay 12 life or 6 red mana to pump +6/+0 onto Ur-Dragon.
5. Let first ability resolve. Ur-Dragon is now Skithiryx, the Blight Dragon.
6. Swing for 10 poison/infect damage. This kills the opponent.
Combo: Commander Damage
Dragon Tyrant + Moltensteel Dragon + Scion of the Ur-Dragon
1. Activate Ur-Dragon ability, targeting Dragon Tyrant.
2. Activate Ur-Dragon ability, targeting Moltensteel Dragon.
3. Let second ability resolve. Ur-Dragon is now Moltensteel Dragon.
4. Pay 10 life or 5 red mana to pump +5/+0 onto Ur-Dragon.
5. Let first ability resolve. Ur-Dragon is now Dragon Tyrant (6/6 +5/+0).
6. Swing for 22 commander damage with Dragon Tyrant's double-strike.
Moltensteel Dragon can be replaced with any dragon that has Firebreathing. See Alternative Firebreathing Creatures.
Moltensteel Dragon can be replaced with pump spells that grant +X/X. See Alternative Damage Pumps.
Atarka, World Render can provide the double-strike necessary, but the combo must be performed before attacking. Dragon Tyrant is better because it has double-strike and 6/6 inherently. This allows the combo to be set up after beginning the combat phase.
Combo: Card Draw To Direct Damage
Curiosity + Niv-Mizzet, the Firemind
1. Tap Niv-Mizzet, the Firemind to draw a card.
2. Triggers Niv-Mizzet, the Firemind ability, deal 1 damage to opponent.
3. Triggers Curiosity, draw a card.
4. (repeat) Triggers Niv-Mizzet, the Firemind ability, deal 1 damage to opponent.
5. Repeat until content with damage done. (Curiosity says "may draw").
Combo: Infinite Attacks - Savage Ventmaw Version
Aggravated Assault + Savage Ventmaw
1. Attack with Savage Ventmaw.
2. Trigger Savage Ventmaw ability, add 3R3G mana to the pool.
3. Use Aggravated Assault ability, costing 3+2R. Untap creatures, including Savage Ventmaw.
4. (repeat) Attack with Savage Ventmaw.
Combo: Infinite Attacks - Hellkite Charger Version
Bear Umbra + Hellkite Charger
1. Enchant Hellkite Charger with Bear Umbra.
2. Attack with Hellkite Charger.
3. Trigger Bear Umbra ability, untap all lands.
4. Pay for Hellkite Charger ability. Untap attacking creatures and enter into a new combat phase.
5. (repeat) Attack with Hellkite Charger.
Note: Any enchantment/equipment with "Whenever ___ creature attacks, untap all lands you control." will work for this combo. See Alternative Infinite Attack Enablers.
Combo: 180 Damage Spike
Rite of Replication + Scourge of Valkas
1. Get Scourge of Valkas into play. (Cast or copy using Scion of the Ur-Dragon)
2. Cast Rite of Replication targeting Scourge of Valkas.
3. Scourge of Valkas trigger ability on all other Scourge of Valkas. X == 6 for original + 5 replicant Scourge of Valkas. 6 dragons * 5 triggers == 30 triggers.
30 triggers * (X=6 dragons) == 180 damage
