I worked on my Darius + Blitz combo, and holy crap we are really getting that down tight.
We both start off with double grab/reach just so they can't escape once we start attack. It got us first kill in under 40 seconds, second kill in the next minute.
We really destroyed this game, fell off mid-late game, but I came back once we hit about 30 minutes in. Amazing game imo, probably could have built him better though.