Sword of Hearth and Home attached to Dragonlord Kolaghan.
An opponent is unable to block and kill Dragonlord Kolaghan.
Steps
Declare Dragonlord Kolaghan and Combat Celebrant as attackers, choosing to exert Combat Celebrant as it attacks.
Combat Celebrant triggers, untapping all other creatures you control and causing you to get an additional combat phase after this one.
Deal combat damage to an opponent with Dragonlord Kolaghan.
Sword of Hearth and Home triggers, exiling Combat Celebrant, then causing you to search your library for a basic land card, then put the land and Combat Celebrant onto the battlefield.
Repeat each combat phase.
Results
Infinite combat damage.
Infinite combat phases.
Infinite ETB.
Infinite LTB.
Near-infinite landfall triggers.
Put all basic land cards from your library onto the battlefield.