Urza, Lord High Artificer + Deadeye Navigator + The Ooze + Arcbound Crusher
Urza, Lord High Artificer
Deadeye Navigator
The Ooze
Arcbound Crusher
Infinite artifact ETBInfinite artifact LTBInfinite artifact sacrifice triggersInfinite artifact tokensInfinite creature ETBInfinite creature LTBCast all spells in your libraryExile your libraryInfinite +1/+1 counters on creatures you controlInfinite Mutagen tokensInfinite blinkingInfinite blue manaInfinite creature tokens
How it works
Activate Arcbound Crusher by paying 1, blinking it.
Arcbound Crusher leaves and reenters the battlefield, causing it to enter with +1/+1 counters due to its modular ability, and triggering The Ooze and Deadeye Navigator's soulbond ability.
Resolve Deadeye Navigator's trigger, repairing it and Arcbound Crusher
Resolve The Ooze's trigger, creating a Mutagen token for each +1/+1 counter that was on Arcbound Crusher when it left the battlefield.
When the Mutagens enter, Arcbound Crsuher triggers that many times, putting a +1/+1 counter on it for each trigger.
Activate Urza's first ability twice by tapping Arcbound Crusher and a Mutagen, adding .