I was thinking of using YGO for a campaign setting. All players would be required to be minion makers and Power Source more their archetype (as in their deck's archetype) (Dark Magician or other mage archetypes for Mystical for example) I would also create several custom rules to further encompass YGO but for most part keep rules the same just tweak or create custom mechanics.
Minion Makers Edits:
Players would use all normal rules but don't need to roll to destroy bonuses to create buffed monsters. Instead when they use it they pick any buff from the monster they want if the Bonus needed is a 3 or 4 however that could be treated as them needing to tribute summon thus have to blow up a monster (3 bonus) or two (4).
Like normal rules in YGO you can only have 5 monsters at any one time. (but there might be moments when they fight using normal rules for all intents and purposes)
Spell and Trap cards will be 'free' actions.
Spells: There will be several that be available throughout the campaign at all times and they'd be a free action. (once per turn)
Traps: These replace Reactions during campaign while some reactions would already be acceptable for any reactions that don't fit a duel they'd be replace with 'trap' reactions.
Abilities be redesigned as effects from spells, traps or monsters.