Key Spirit monsters that provide consistency include "Aratama", a monster searcher, "Nikitama" and "Sakitama", who grant extra Normal Summons to Spirits, and "Konohanasakuya", a Special Summon extender with a GY effect to let a Spirit monster stay on the field (by preventing its return-to-hand effect from activating)
But I still think it is fun enough that players wont care
Instead of just aiming to deck an opponent out, mill payoffs let you turn every lost card into an advantage that pushes you closer to victory
Anax and Cymede Daxos of Meletis Elspeth, Sun's Champion Heliod, God of the Sun Medomai the Ageless Spear of Heliod Triad of Fates
But, of course, you can still use the Manaphy from Brilliant Stars if you really need the protection
There are plenty of powerful cards to play without multiple mana symbols, and its powerful with commanders that cost or have a cost of like Niv-Mizzet Reborn or Jodah, Archmage Eternal