Sméagol, Helpful Guide, Dúnedain Rangers, Zendikar's Roil, and Phyrexian Altar

Prerequisites

• Sméagol, Helpful Guide on the battlefield
• Dúnedain Rangers on the battlefield
• Zendikar's Roil on the battlefield
• Phyrexian Altar on the battlefield
• You don't control a Ring-bearer
• You have a land card in hand

Steps

1. Play a land card, triggering Dúnedain Rangers and Zendikar's Roil
2. Resolve the Zendikar's Roil trigger, creating a 2/2 Elemental creature token
3. Resolve the Dúnedain Rangers trigger, causing the Ring to tempt you, and causing the Elemental token to become your Ring-bearer
4. Sméagol triggers
5. Holding priority, activate Phyrexian Altar by sacrificing the Elemental, adding one mana of any color
6. Resolve the Sméagol trigger, causing an opponent to reveal cards from the top of their library until they reveal a land card, then causing you to put the land onto the battlefield tapped under your control, and your opponent to put all other revealed cards into their graveyard
7. When the land enters the battlefield, Dúnedain Rangers and Zendikar's Roil trigger
8. Repeat from step 2
9. NOTE: This combo can be stopped if an opponent runs out of lands in their library, so it is recommended to alternate opponents in between cycles to maximize the amount of iterations

Results

• Near-infinite colored mana
• Near-infinite death triggers
• Near-infinite ETB
• Near-infinite landfall triggers
• Near-infinite LTB
• Near-infinite mill
• Near-infinite sacrifice triggers
• Put all land cards from your opponents' libraries onto the battlefield tapped under your control