You are able to reduce the affinity creature's cost by ({2} magic symbol) or more.
Steps
Activate
Spirit en-Kor's equip ability by paying ({0} magic symbol) , targeting the affinity creature.
Monk Gyatso triggers, airbending the targeted creature.
The
Spirit en-Kor ability fizzles due to no longer having a legal target.
Cast the creature from exile by paying ({0} magic symbol) due to its affinity ability.
Repeat.
Notes
You want to reduce the affinity creature's cost by ({2} magic symbol) or more using its affinity ability. For example, if you choose Ancestral Statue, you need to control two or more attacking creatures.