Sword of Hearth and Home attached to Dragonlord Kolaghan.
An opponent is unable to block and kill Dragonlord Kolaghan and Port Razer.
Steps
Deal combat damage to an opponent with Dragonlord Kolaghan and Port Razer, triggering Sword of Hearth and Home and Port Razer.
Resolve the Port Razer trigger, untapping all creatures you control and causing you to get an additional combat phase after this one.
Resolve the Sword of Hearth and Home trigger, exiling Port Razer, then causing you to search your library for a basic land card, then put the land and Port Razer onto the battlefield.
Repeat each combat phase.
Results
Infinite combat damage.
Infinite combat phases.
Infinite ETB.
Infinite LTB.
Infinite mana creatures you control can produce.
Infinite untap of creatures you control.
Near-infinite landfall triggers.
Put all basic land cards from your library onto the battlefield.