Blueno started his own bar about five years ago in the backstreets of Water Seven, calling it simply "Blueno's Bar." It was in a seedy side of town, where vagrants and ne'erdowells coalesced, but he at least acted happy. In truth, alas, it wasn't so: Blueno was a covert agent of the government's sent to steal the plans to an Ancient Weapon.

It was in this fashion that Blueno met the supposed hidden king of Water Seven, Franky, and the two struck up a friendship of sorts. Again, it wasn't really so, but that friendship had some repercussions later on.

Blueno ate the Doa Doa no Mi (Door Door Fruit) which allows him to create doors on any surface. He has even created "air doors", doors in the air itself, which lead to what seems to be another dimension. Blueno is also able to create doors on people, and did so to Luffy's face, causing it to spin like a revolving door.

Blueno's tekkai seems to be the one of the more powerful ones of the group, and he was the first to reveal any variations of the move.

(Source: arlongpark.net)