Watch the youtube vid on it. or even better, listen to
advice.
It is relatively simple. Before you steal his items be sure to
put your teammates to the corners of the map and use the Tactic:
Wait There or something. Before you even leave Treasure Town, bring
a pure seed or a trawl orb with you. The pure seed teleports the
eater to the stairs, and when you use the trawl orb, go to the room
with the stairs then use the orb. The items will be pulled into the
room; gather the ones you want then exit through the stairs.If the
store is close to the stairs (the nerby room), then steal the items
at the shop, say no to paying, then throw a stun seed at him or use
a petrify orb. These ensure that if you don't attack him he stays
frozen. If you have X-ray specs, look for the red dots that move
extremely fast every time you move. Or if a kecleon starts
attacking your teammates, use a rollcall orb to warp them to you.
You should still be safe to get to the stairs.I believe Midnight
Forest has Kecleon shops every 5 stairs. The good thing, he always
sells evolution items.