@pyromonki:
Ya know, /a/ actually had a nice discussion about his powers and they actually do make sense when you read these pages:
They really, really don't.
http://www.mangareader.net/bleach/456/10
He's altering the past of the people he cut, you'd think this means their memories but:
http://www.mangareader.net/bleach/456/11
He is literally inserting HIMSELF into that past event, however, notice he says into the person he cuts? That means that person's past ONLY and no one else, creating an alternate timeline where he interacted with that person. And the killer is… He was ACTUALLY THERE.
Which actually explains why Chad and Orihime couldn't "see the logical fallacy" , Tsukishima AND Ichigo were actually there in the past in THEIR timeline. (Hence, they probably really do have a picture of Tsukishima in their room):
http://www.mangareader.net/bleach/456/12
Please forgive me for defending Bleach.
You can't physically insert you into another persons past, and then not alter the past of everyone they know as well. That's just impossible. Either Tsukishima was there, or he wasn't. The fact that only Chad and Orihime believed the ridiculous notion that Tsukishima helped beat Aizen shows that he really didn't, it's just them who believe that. And while Tsukishima talks about Orihimes past or Chads pendant, neither of those bits of info are too hard to figure out by simple research beforehand; there was nothing indicating that Tsukishima had, you know, actually raised Orihime since she was a child.
Then suddenly Tsukishimas power becomes retroactive time travel, when he cuts the monument. Now he has physically been there in the past, effectively reshaping reality: he has changed everyones past, and as a result the trap affects Byakuya.
Then it shifts again, and Tsukishima has been a part of Byakyas life for an eternity, and knows all his tricks. Except not really because Tsukishimas not several centuries old, and Byakuya gives no indication that he's ever seen this dude in his life before. Not even a line of "You broke the law, I'll kill ya former mentor or not".
And then finally, Tsukishima reveals that he DOESN'T know everything about Byakuya, bringing the stupid full circle.
@pyromonki:
We used to think that was a figure of speech, but he literally means it. Hence how he knows everything about everyone he cuts from that past point. He experienced it.
His only limit is that he can't change past events, only put himself somewhere in it. .
But it does change the past. That's why his power is so ridiculously broken and plothole inducing. When Tsukishima inserts himself in the place of Orihimes Brother, what become of all the subsequent events in her life shaped by her brothers actions, for instance the time he became a hollow and attacked her? Did that just not happen anymore?
And if Tsukishima makes the past of his victims real, and experiences it himself…
Does that mean that by brainwashing Ginjo, Tsukishima somehow really did murder a bunch of fullbringers and a shinigami, who never existed?