Each attack mills a ton of cards from your opponent, depriving them of a lot of resources they may need to win the game
There are no doubt decks like Jared Cathalion that enjoy the fact everything is a rainbow, but the mana fixing part probably isnt enough to run this thing on its own
Creature (28) Lunarch Veteran x3 Selfless Savior Skyclave Apparition x2 Soul Warden x4 Heliod, Sun-Crowned x4 Trelasarra, Moon Dancer x4 Voice of the Blessed x4 Ranger-Captain of Eos x2 Scurry Oak x4 Instant (4) Enchantment (4) Land (24) Branchloft Pathway x4 Castle Ardenvale x2 Forsaken Crossroads Overgrown Farmland Plains x8 Sunpetal Grove x4 Temple Garden x4 Sideboard (15) Ajani, Strength of the Pride x2 Cleansing Nova Declaration in Stone x2 Dromoka's Command x2 Giant Killer Gideon Blackblade Rest in Peace Skyclave Apparition x2 Thalia, Guardian of Thraben x2 Yasharn, Implacable Earth Lets use a list from the Hooglandia Open as an example
Higher rarities, such as Hyper Rare, are marked with variants of these symbols
I collect Flareon because I like it, idc about anything else