Main usage command is /cmi usermeta [playerName] [add/remove/clear/list/increment] (key) (value) (-s)
This command provides option you to add special values to thew player and reuse them when needed with %cmi_user_meta_[key]% placeholder.
This can range from some generic information you want to add to player to information like death counter.
So lets make a death counter for the player. Initial command will be /cmi usermeta Zrips add deaths 0 -s where Zrips is players name who should get this, add will indicate that we want to add special date to the player, deaths are some custom name for this and it can be whatever you want, 0 is initial value, and -s will simply perform this command without informing playe.
Now we can retrieve this data with %cmi_user_meta_[key]% placeholder which will return 0.0 yes, it will return with fraction. So in this case lets use %cmi_user_metaint_[key]% and our exact placeholder should look like %cmi_user_metaint_deaths% which will return 0.
Now lets manipulate this value. After all we want to increase this value when player dies. So lets add command to eventCommands.yml file under playerDeath category. Command itself will looke like /cmi usermeta [playerName] increment deaths +1 -s this will increase current value by 1 without showing feedback message. Same thing can be done with -1 or any value you want which will (if possible) change current value by appropriate value. And after performing this command %cmi_user_metaint_deaths% placeholder will return 1 instead of 0, after second time you will get 2 and so on.