When considering upgrades for this deck, Grand Arbiter Augustine IV is worth a look-in owing to how it reduces the cost of your blue and white spells, and (rather cruelly) taxes your opponents for every spell they cast
Do you have creatures and Tidus in play
Rite of Harmony is a cheap sorcery that represents the druidic wisdom of the Elf tribe
Free spells + Y'shtola, Night's Blessed: Spells that cost 0 mana but have a mana value of 3 or more are perfect fuel for your commander
It has prices for every card (sourced from TCGplayer), lets you create a wishlist, and has a trading calculator that adds your cards on one side and the other persons on the other, so you always know how much everythings worth
Though still a victim of the modern TCGs power creep, this is a much more capable card than the older ones on this list, with 160 HP and two decent attacks too, including one that deals 150 HP damage