User blog comment:Xilinoc/Ch. 561 - THE VILLAN/@comment-24113610-20131211130301/@comment-11051098-20131211153908

The Sternritters are overpowered, yes, but that's exactly what the manga needs - a real challenge for the captain-level Shinigami. The Espada were pictured as being on captain-level, a group they had to defeat for the sake of the world, but only like half of them had power or abilities that made them a real challenge to defeat.

Mask beating up Kensei annoys me because Kensei is one of my favorite captains. But I'm not bothered because Mask is overpowered - I'm bothered because the whole "cheer on Mask and he gets insane strong" thing is ridiculous. It's the most stupid thing I've seen so far in Bleach. Original, yes, as far as I'm concerned, but having another person to act as the source to power up your special ability is a disadvantage.

Now that James is dead, Mask's "Superstar" should logically fail and his power decrease to its original level, which should make him easily defeated.