Kate Stewart, Intruder Alarm, Hourglass of the Lost, and Mishra, Eminent One

Prerequisites

• Kate Stewart on the battlefield
• Intruder Alarm on the battlefield
• Hourglass of the Lost on the battlefield
• Mishra, Eminent One on the battlefield

Steps

1. At the beginning of your combat phase, Mishra triggers, creating a token copy of Hourglass of the Lost that is a 4/4 artifact creature named Mishra's Warform with haste
2. Activate Mishra's Warform's first ability by tapping it, adding and putting a time counter on it
3. Kate's first ability triggers, creating a 1/1 Soldier creature token
4. When the Soldier enters, Intruder Alarm triggers, untapping all creatures
5. Repeat from step 2

Results

• Infinite ETB
• Infinite creature tokens
• Infinite mana creatures you control can produce
• Infinite untap of creatures
• Infinite untap of creatures you control
• Infinite white mana
• Infinitely large creatures you control until end of turn