The suggestion is simply....add a potion, through CS(shouldn't be many diamonds considering it's effect) or Alchemy that reduces player level temporarily to the level they choose. Maybe for 2 hours?
Why? Why not? No, there are(albiet few) reasons for it. The obvious one is item farming, drop rate reduces the further you are from monster level. The other reason is titles. Certain titles(i.e. Great Master of the Bear King, Master of the Bear King, Lone Ranger, Nemesis of the Undead, Wanted by the Zurhidon, and one for Paspers) require you to be a certain level or below. The only current way to get these titles on a character with all 3 classes above said level is Fruit of Forgetting. Which is a damn big commitment for farming or a few titles.
Naturally, one could only use items of that level or below, and skills would be capped to that level.