When Urza enters the battlefield, it and Deadeye Navigator's soulbond ability trigger twice.
Resolve both Deadeye Navigator triggers, repairing it and Urza.
Resolve both Urza triggers, creating two 0/0 Construct artifact creature tokens.
Activate Urza's first ability twice by tapping the Constructs, adding .
Repeat.
This clever loop transforms Urza, Lord High Artificer and Deadeye Navigator into a self-sustaining engine by taking full advantage of soulbond to constantly reset Urza. Elesh Norn, Mother of Machines serves as a powerful amplifier here, doubling Urza's entry trigger so that each blink yields two Construct artifact creature tokens instead of one. Those very same tokens can be tapped for blue mana using Urza's built-in mana ability, easily paying the blink cost while leaving you with an endless army of artifact creatures.