Compared to the Amber/Amethyst deck that has multiple copies of Friends From the Other Side, as well as Part of Your World, Hades, Lord of the Underworld, and Dr
Sapphire can easily bump up Ambers ink ramp with One Jump Ahead
Little John has so much synergy with this deck, he demands to be included
Not into it
Legendary Creature - Assassin Yuffie, Materia Hunter Ninjutsu (, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.) When Yuffie enters, gain control of target noncreature artifact for as long as you control Yuffie
Both commander choices are great for the deck, and unlike most cases, where there's a clear "best" commander, the choice between Tidus and Yuna is completely up to personal preference (although Yuna is the stronger of the two)