Rikimaru is the bane of low level pub games because his damage becomes RIDICULOUS if you let him hit you in the back. The key to beating this is trading hits with the riki when he goes in to right click, assuming you don't have a hero disadvantage.
His item build is still pretty standard with time, but I basically spend about 10-15 minutes circlejerking about how great I think vangaurd fills Riki's weaknesses and allows him to do more damage/play more aggressive, so get ready for that.
Anyways, I hope that you guys get stomped by riki less now!
Match ID: 405759800