Infinite ETB, Infinite LTB
Activate Combine Guildmage's first ability by paying and tapping it, causing each creature you control to enter the battlefield with a +1/+1 counter on it this turn.
Activate another creature you control that has a +1/+1 counter on it by exiling it, creating a 1/1 Human creature token that enters the battlefield with a +1/+1 counter on it due to Combine Guildmage.
Repeat step 2 using the Human token instead.
Component Cards
How It Works
Activate Combine Guildmage's first ability by paying and tapping it, causing each creature you control to enter the battlefield with a +1/+1 counter on it this turn.
Activate another creature you control that has a +1/+1 counter on it by exiling it, creating a 1/1 Human creature token that enters the battlefield with a +1/+1 counter on it due to Combine Guildmage.
Repeat step 2 using the Human token instead.