>>54133258I'd copy the Draconian Quest system from DQXI. You can turn on the quests at the start of the game only, and you can't trade with other players until the quests are completed or turned off, but you can turn them off at any time. Each Draconian Quest (or Pokemonium Quest?) you complete gives you a huge reward at the end of the game. Some examples of these quests would be:
>If a Pokemon faints, it can't be revived until the end of the game>Cannot use bag items in battle>Cannot purchase battle items other than Pokeballs>TMs are one time use (returned to you after you beat the game)>Level caps depending on the gym leader (ie, if the 3rd gym leader's strongest Pokemon is level 25, none of your Pokemon can be level 25 or higher)>All money you earn in battle is held in a bank until the end of the game. You can still earn money from selling items.>Your Pokemon don't gain any stats from EVs, though they still gain EV points from battle 