Cast Fiend Hunter by paying {1}{W}{W}.
Fiend Hunter enters the battlefield, exiling Crypt Champion.
Activate Goblin Bombardment by sacrificing Fiend Hunter.
Fiend Hunter leaves the battlefield, returning Crypt Champion from exile to the battlefield.
Crypt Champion enters the battlefield, triggering its first and second abilities.
Resolve the first Crypt Champion trigger, returning Fiend Hunter from your graveyard to the battlefield.
Repeat from step 2.
Once you have a large amount of Goblin Bombardment triggers, you may stop the loop and deal infinite damage to any target(s).

Infinite damage

Infinite death triggers

Infinite ETB

Infinite LTB

Infinite sacrifice triggers

Crypt Champion

Fiend Hunter

Goblin Bombardment

Cast Crypt Champion by paying {3}{B}, ensuring not to spend {R} to cast it.
Crypt Champion enters the battlefield, triggering its first and second abilities.
Holding priority, activate Saffi by sacrificing it, targeting Crypt Champion.
Resolve the first Crypt Champion trigger, returning Saffi from your graveyard to the battlefield.
Resolve the second Crypt Champion trigger, sacrificing it.
Saffi triggers, returning Crypt Champion from your graveyard to the battlefield.
Repeat from step 2.

Saffi Eriksdotter

Cast Glasspool Mimic by paying {2}{U}, without using {R}, having it enter the battlefield as a copy of Crypt Champion.
Glasspool Mimic enters the battlefield, triggering its first and second abilities.
Resolve the second Glasspool Mimic trigger, causing you to sacrifice it.
Resolve the first Glasspool Mimic trigger, returning Glasspool Mimic from your graveyard to the battlefield as a copy of Crypt Champion.
Repeat from step 2.

Glasspool Mimic // Glasspool Shore

Cast Fiend Hunter by paying {1}{W}{W}.
Fiend Hunter enters the battlefield, exiling Crypt Champion.
Activate Ashnod's Altar by sacrificing Fiend Hunter, adding {C}{C}.
Fiend Hunter leaves the battlefield, returning Crypt Champion from exile to the battlefield.
Crypt Champion enters the battlefield, triggering its first and second abilities.
Resolve the first Crypt Champion trigger, returning Fiend Hunter from your graveyard to the battlefield.
Repeat from step 2.

Infinite colorless mana

Ashnod's Altar

Cast Mirror Image by paying {2}{U}, without using {R}, having it enter the battlefield as a copy of Crypt Champion.
Mirror Image enters the battlefield, triggering its first and second abilities.
Resolve the second Mirror Image trigger, causing you to sacrifice it.
Resolve the first Mirror Image trigger, returning Mirror Image from your graveyard to the battlefield as a copy of Crypt Champion.
Repeat from step 2.

Mirror Image

Cast Fiend Hunter by paying {1}{W}{W}.
Fiend Hunter enters the battlefield, exiling Crypt Champion.
Activate Phyrexian Altar by sacrificing Fiend Hunter, adding one mana of any color.
Fiend Hunter leaves the battlefield, returning Crypt Champion from exile to the battlefield.
Crypt Champion enters the battlefield, triggering its first and second abilities.
Resolve the first Crypt Champion trigger, returning Fiend Hunter from your graveyard to the battlefield.
Repeat from step 2.

Infinite colored mana

Phyrexian Altar

Cast Phantasmal Image by paying {1}{U}, without using {R}, having it enter the battlefield as a copy of Crypt Champion.
Phantasmal Image enters the battlefield, triggering its first and second abilities.
Resolve the second Phantasmal Image trigger, causing you to sacrifice it.
Resolve the first Phantasmal Image trigger, returning Phantasmal Image from your graveyard to the battlefield as a copy of Crypt Champion.
Repeat from step 2.

Combos with "Crypt Champion"