Activate Ashnod's Altar by sacrificing Torsten, adding {C}{C}.
Torsten dies, triggering itself and Nim Deathmantle.
Resolve the Torsten trigger, creating seven 1/1 Soldier creature tokens.
Activate Ashnod's Altar by sacrificing a Soldier, adding {C}{C}.
Resolve the Nim Deathmantle trigger from step 2, causing you to pay {4} to return Torsten from your graveyard to the battlefield, and attach Nim Deathmantle to it.
Torsten enters the battlefield, allowing you to search the top seven cards of your library and put any number of creature and/or land cards from them into your hand.
Repeat.

Infinite colorless mana

Infinite creature tokens

Infinite death triggers

Infinite ETB

Infinite LTB

Infinite sacrifice triggers

Put any number of creature and/or land cards from your library into your hand

Torsten, Founder of Benalia

Nim Deathmantle

Ashnod's Altar

Activate Phyrexian Altar by sacrificing Torsten, adding {1}.
Torsten dies, triggering itself and Nim Deathmantle.
Resolve the Torsten trigger, creating seven 1/1 Soldier creature tokens.
Activate Phyrexian Altar three times by sacrificing three Soldiers, adding {3}.
Resolve the Nim Deathmantle trigger from step 2, causing you to pay {4} to return Torsten from your graveyard to the battlefield, and attach Nim Deathmantle to it.
Torsten enters the battlefield, allowing you to search the top seven cards of your library and put any number of creature and/or land cards from them into your hand.
Repeat.

Infinite colored mana

Phyrexian Altar

Activate Phyrexian Altar by sacrificing Torsten, adding {1}.
Torsten dies, triggering itself and Enduring Renewal.
Resolve the Torsten trigger, creating seven 1/1 Soldier creature tokens.
Resolve the Enduring Renewal trigger, returning Torsten from your graveyard to your hand.
Activate Phyrexian Altar six times by sacrificing six Soldiers, adding {4}{G}{W}.
Cast Torsten by paying {5}{G}{W}.
Torsten enters the battlefield, allowing you to search the top seven cards of your library and put any number of creature and/or land cards from them into your hand.
Repeat.

Infinite storm count

Enduring Renewal

Activate Mirage Mirror by paying {2}, causing it to become a copy of Myth Unbound until end of turn.
Activate Phyrexian Altar by sacrificing Torsten, adding {G}. Choose to return Torsten to the command zone from your graveyard.
Torsten's second ability, Myth Unbound and Mirage Mirror trigger.
Resolve the Torsten trigger, creating seven 1/1 Soldier creature tokens.
Resolve the Myth Unbound and Mirage Mirror triggers, causing you to draw two cards. 
Activate Phyrexian Altar six times by sacrificing six Soldiers, adding {5}{W}.
Cast Torsten from the command zone by paying {5}{G}{U} and without commander tax due to Myth Unbound and Mirage Mirror.
Repeat from step 2.

Combos with "Torsten, Founder of Benalia"