Yannik, Scavenging Sentinel, Glorious Protector, and Felidar Guardian

Prerequisites

• Yannik, Scavenging Sentinel in hand or in the command zone
• Glorious Protector in hand or in exile
• Felidar Guardian on the battlefield
• plus enough mana to pay for commander tax, if applicable, plus if Glorious Protector was not foretold available

Steps

1. Cast Yannik by paying plus commander tax, if applicable
2. Yannik enters the battlefield, triggering itself, exiling Felidar Guardian until Yannik leaves the battlefield and triggering the last part of its ability
3. Resolve this trigger, putting a +1/+1 counter on any target creature
4. Cast Glorious Protector by paying
5. Glorious Protector enters the battlefield, triggering itself, exiling Yannik and any number of other non-Angel creatures you control until Glorious Protector leaves the battlefield
6. Felidar Guardian returns from exile to the battlefield due to Yannik leaving the battlefield, triggering itself, blinking Glorious Protector
7. Yannik returns from exile to the battlefield without using the stack due to Glorious Protector leaving the battlefield
8. When Yannik and Glorious Protector enter the battlefield, they each trigger themselves
9. Resolve Yannik's trigger, exiling Felidar Guardian until Yannik leaves the battlefield and triggering the last part of its ability
10. Resolve this trigger, putting a +1/+1 counter on any target creature
11. Resolve the Glorious Protector trigger, exiling Yannik until Glorious Protector leaves the battlefield
12. Repeat from step 6

Results

• Infinite +1/+1 counters on all creatures you control besides Yannik, Guardian Protector, and Felidar Guardian
• Infinite blinking of Guardian Protector and non-Angel creatures you control
• Infinite ETB
• Infinite LTB