Felidar Guardian, and Portcullis

Prerequisites

• Felidar Guardian in hand
• Portcullis on the battlefield
• Any two additional creatures on the battlefield under the control of any player or players
• available

Steps

1. Cast Felidar Guardian by paying
2. Felidar Guardian enters the battlefield, triggering itself and Portcullis
3. Resolve the Portcullis trigger, exiling Felidar Guardian and creating a delayed triggered ability
4. Resolve the Felidar Guardian trigger, blinking Portcullis
5. When Portcullis leaves the battelfield, Portcullis's delayed triggered ability triggers, returning Felidar Guardian and any other creatures exiled with Portcullis from exile to the battlefield
6. When these creatures enter the battlefield, Felidar Guardian and Portcullis trigger
7. Repeat from step 3
8. End the loop by choosing not to blink Portcullis with Felidar Guardian in step 4

Results

• Infinite blinking
• Infinite ETB
• Infinite LTB