Side Step is a nice part of the Flow Like Water + Defensive Energy deck. If you aren't in a defense synergy deck, blocking with allies, stunning, or using tough cards is generally a better way to prevent damage. There are a bunch of 1-cost defenses, but unlike Never Back Down or Desperate Defense, you don't need to defend with your hero's basic power. If you are trying to trigger things like Hard to Ignore or Unflappable, you might want a few extra ways to prevent damage like Energy Barrier, because villains will often attack for more than 3 damage. Jump Flip is another close comparison that I prefer because Protection is light on threat removal, but in the Flow Like Water deck you can definitely play both.