An opponent cannot block and kill creatures you control.
Steps
Declare Godo as an attacker, triggering its second ability and Shaun's first ability.
Resolve the Shaun trigger, creating a tapped and attacking copy of Godo that is a nonlegendary Synth in addition to its other types.
When the Godo token enters the battlefield, its first ability triggers, allowing you to search your library for an Equipment card and put it onto the battlefield.
Resolve the Godo trigger from step 1, untapping it and all Samurai you control and causing you to get an additional combat phase after this one.
Repeat each combat phase.
Results
Infinite combat phases.
Infinite creature tokens with haste.
Infinite ETB.
Infinite untap of Samurai you control.
Put all Equipment from your library onto the battlefield.