There were a few times in the video where what appeared to be the opportunity for combo like kills was offered. [url=http://i.imgur.com/rhHsiLS.jpg]Here[/url], just after a hunter killed an enemy with a throwing knife, we see "Chain Reaction x1" with a 10 second timer. [url=http://i.imgur.com/nnW1wWO.jpg]Later[/url], after a hunter snipes an enemy, we see "Death's Dance x1, again with a 10 second timer. [url=http://i.imgur.com/aHKHXQT.jpg]Still later[/url], we see a hunter get another "Chain Reaction x1". This time with a pistol. Earlier in the video, we see a hunter reach "Chain Reaction x2". The first shot is a [url=http://i.imgur.com/ASPnuyu.jpg]headshot[/url], which kills one fallen. Followed quickly by a [url=http://i.imgur.com/8E2x8Bj.jpg]second headshot[/url], which kills another. [Thanks to Corneilius86 for pointing this one out.] What exactly these multipliers do is anybody's guess.