How can you create a combo with Yurlok of Scorch Thrash, Umbral Mantle, Training Grounds?
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[START OF COMBO]This combo can be formed with Yurlok of Scorch Thrash, Umbral Mantle, Training Grounds

Color identity: UBRG
Mana cost: {1}
Steps:
  1. Activate Yurlok of Scorch Thrash by paying {1} and tapping it, causing each player to add {B}{R}{G}
  2. Activate Yurlok of Scorch Thrash by paying {1} and untapping it, causing itself to get +2/+2 until end of turn.
  3. Repeat an arbitrarily large amount of times.
  4. It is strongly recommended to empty your mana pool using a mana sink before proceeding.
  5. Move to your next step or phase, causing each player to lose life equal to the amount of unspent mana in their mana pool.
  6. Each player whose mana pool contained an amount of mana equal to or greater than their life total loses the game due to having 0 or less life, which causes a draw if every player lost the game.[END OF COMBO STEPS]

Result:
  - Draw the game
  - Infinite black mana for all players
  - Infinite green mana for all players
  - Infinite lifeloss
  - Infinitely large Yurlok until end of turn
  - Infinite red mana for all players[END OF COMBO RESULT][END OF COMBO]

Other prerequisites:
  - All permanants must be on the battlefield
  - Umbral Mantle attached to Yurlok of Scorch Thrash.
  - Yurlok of Scorch Thrash does not have summoning sickness.
[END OF COMBO PREREQUISITES]
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