Kyler, Sigardian Emissary + Presence of Gond + Devoted Druid + Maskwood Nexus

Kyler, Sigardian Emissary

Presence of Gond

Devoted Druid

Maskwood Nexus

How it works

1. Activate Devoted Druid by tapping it, creating a 1/1 Elf Warrior creature token.
2. The Elf Warrior enters the battlefield, triggering Kyler, putting a +1/+1 counter on itself.
3. Activate Devoted Druid's second ability by putting a -1/-1 counter on it, untapping it.
4. Repeat.