Port Razer combo attack undefended player repeat till dead.  With Stalking Vengeance, the token will kill another player possibly.  Use Bonds of Discipline to lock down player if needed.

Karn's ability use to create artifact creature, Commander copies it, Gonti's gets energy triggers, Panharmonicon doubles those, get addition turn, repeat.

Lightning Runner same as above, creates endless turn loop.

Ditto Aetherminer, with Pan or Gonti out flicker and get endless energy.