Rin Nishimura
Although Rin stood behind the obvious intruder, he still got no response whatsoever. "You're a talkative one, aren't you?" Rin proclaimed as he moved closer. As he did, though, he noticed a lot of commotion going around him, it seemed he wasn't the only one to take to the air. Shinigami were battling all throughout the Seireitei. At that point, the intruder turned around, looking a lot like most of the other intruders. Was he just a copy? Rin thought to himself as the not-very-nice-looking intruder came towards him. Rin barely had the time to jump back, drawing his Zanpakuto in the progress.
"If that's the way you want to do it... Cleanse the fields, Tsukiakari!" A sudden bright flash enveloped the area close to Rin, potentially blinding his adversary. When the flash faded out, white particles were the first things to reach the opponent, occasionally mixed in with indigo particles as one looked closer to the source. And the source being Rin, with his released Zanpakuto. Not wasting any time, he shunpoed in front of the thing and sent the blade flying straight toward the sternum of his foe.
Yet, instead of letting it impale, Rin set his free hand on the shoulder of the thing. "Taste the jaws of clarity!" As he yelled out, the blade of his sword split enough to cover the whole circumference of the torso, before engulfing it in one clean bite. With a loud crunch, the body split into two, but instead of crumbling down, the lower of the two parts remained standing, as the upper used Rin's loss of focus to make a deep gash along his right arm, before he was able to trash him away.
Blood dripped down as Rin watched the two parts growing out new parts, with the end result being two of those things in front of Rin. The gruesome growing performance ended and both of them moved on to focus on the smell of blood coming from Rin. Or at least that's how he envisioned it. "Multiplying won't help you look better, bastard. Come and get me."