demoman?

'blob style' was just what casters called it, just the short version of x6 with their very unique aggressive play style. which you didn't see other teams really doing during that season IMO

every team has their own style, if other teams just tried to copy each other they would be way too predictable which is why you don't see it. different players create different chemistry. x6 had really great comms too everyone on that team was so in sync because of how vocal they were and how quickly they were to follow up on each other or just have the best timing in different situations

when teams push off-uber they still blob constantly

and as defy said, a lot of times x6 would just coordinate things so well that their combo and flank would like attack the enemy in perfect unison (especially on mid fights), so it may have resembled a "blob", they still very much had a combo and a flank

it doesn't work without vhalin. the blob just isn't big enough. there aren't many players that can match his normal weight in the first place, and not many of them are able and willing to put on that extra forty pounds

it also did some pretty gross things to the skin

http://i.imgur.com/D61qg.jpg

look at tiny widdle oov :3