I absolutely love multicolored-based sets, as they usually have a ton more depth than normal sets - since a lot of the cards can overlap in different archetypes and the power level is often quite a bit higher since the cards have a much higher barrier in terms of their mana requirements
While you shut down the ability to deal commander damage, Phyresis lets you win the game even faster since the amount of damage you have to do is cut in half to have someone lose the game
However, it still is a serious threat for certain land based strategies
The Plenty to Go Around ability lets you remove a point of damage from each of your characters at the end of your turn, and then ready each character you removed damage from
If we can drop a Breaker of Armies onto the field with Purphoros' Sneak Attack ability, Alena will let us turn that into mana so we can play an Eldrazi Titan or some other giant creature
They arent all good, but most are pretty powerful in comparison to what we did have