I tried this and i thought i could share this little tutorial with beginners , cause it's not that difficult but not everyone are able to make this so here is a tutorial on how to make some kind of killing spree counter
I will explain simply , the event will check the variable Killed so if it's equal to 0 this will be the first kill , if the variable equal 1 this will be a double kill .. etc i hope this helps the people who are looking for this kind of things !
PS : Don't forget to set the variable as Global in the check Variable Step :)