How can you create a combo with Rootha, Mercurial Artist, Increasing Vengeance?
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[START OF COMBO]This combo can be formed with Rootha, Mercurial Artist, Increasing Vengeance

Color identity: UR
Mana cost: {2}{R}{R}, plus enough mana to cast the additional instant or sorcery
Steps:
  1. Cast an instant or sorcery spell, or wait for an opponent to cast one.
  2. Holding priority, cast Increasing Vengeance by paying {R}{R}, targeting the spell.
  3. Activate Rootha by paying {2} and returning it to your hand, copying Increasing Vengeance, with the copy targeting the original Increasing Vengeance.
  4. Resolve the copy of Increasing Vengeance, copying Increasing Vengeance, targeting the original Increasing Vengeance.
  5. Repeat step 4.[END OF COMBO STEPS]

Result:
  - Infinite magecraft triggers[END OF COMBO RESULT][END OF COMBO]

Other prerequisites:
  - Rootha, Mercurial Artist must be on the battlefield
  - Increasing Vengeance must be in your hand
  - You have an additional instant and/or sorcery card in hand.
[END OF COMBO PREREQUISITES]
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