It is only useful when there are two wizards or more. When you do damage, heal or taunt a mob you generate threat. Whatever wizard has the highest threat will always be aimed for. Calm reduces that threat, it other words it makes mobs less likely to hit you.
The general strategy with calm is a life wizard heals then casts calm so the life wizard does not get hit and defeated.
Yes, (maybe not not sure) have their version of this card. According to the last KI Live it is the most unused spell in the game. I think a lot of people don't really realize that is what it is for. - has Taunt which increases the threat on themselves so that the enemy will attack them instead of their friends more often. Even on my Ice though I like never use that. Especially the X Pip threat? It's like what? Why would I use that? Can't I attack and generate threat that way? Good luck!
(maybe not 
- has Taunt which increases the threat on themselves so that the enemy will attack them instead of their friends more often. Even on my Ice though I like never use that. Especially the X Pip threat? It's like what? Why would I use that? Can't I attack and generate threat that way? Good luck!