When Urza enters the battlefield, it and Deadeye Navigator's soulbond ability trigger.
Resolve the Deadeye Navigator trigger, repairing it and Urza.
Resolve the Urza trigger, creating a 0/0 Construct artifact creature token and a Map token.
Activate Urza's first ability twice by tapping the Construct and Map, adding .
Repeat.
This dazzling engine gets its endless momentum from Urza, Lord High Artificer and Deadeye Navigator working in tandem, where Urza's mana ability pays to repeatedly blink itself and the Navigator using its own soulbond pairing. Every time Urza re-enters the battlefield, it triggers Worldwalker Helm's replacement effect to flood the board with both a massive Construct token and an extra Map token. Those very same tokens can immediately be tapped for blue mana thanks to Urza's built-in artifact mana ability, generating a surplus of mana that fuels the entire loop indefinitely!