Infinite green mana, Infinite mana creatures you control can produce, Infinite untap of creatures you control, Infinite +1/+1 counters on creatures you control
Activate Immaculate Magistrate by tapping it, putting a +1/+1 counter on it for each Elf you control.
Activate Immaculate Magistrate using Devoted Druid's second ability by putting a -1/-1 counter on it, untapping it.
Repeat.
Once you have infinite +1/+1 counters on Immaculate Magistrate, you may instead target any other creature, or use Devoted Druid's first ability.
If you give other creatures +1/+1 counters, you may also untap them infinitely using Devoted Druid's second ability.
Component Cards
How It Works
Activate Immaculate Magistrate by tapping it, putting a +1/+1 counter on it for each Elf you control.
Activate Immaculate Magistrate using Devoted Druid's second ability by putting a -1/-1 counter on it, untapping it.
Repeat.
Once you have infinite +1/+1 counters on Immaculate Magistrate, you may instead target any other creature, or use Devoted Druid's first ability.
If you give other creatures +1/+1 counters, you may also untap them infinitely using Devoted Druid's second ability.