Welcome to the Master Plan

So there are some differences that will be noticeable in comparison to a canon!Izaya.

Appearance
Generally, Pecha is more pale, having spent about 100 days in underground caves with torchlight creating their days and nights. And while Pecha was part of the team that served the Judges and thus received more privileges than the regular blanks who played in games, there was a ranking order and if Uroboros, his unit, ever reached last place out of the three, the conditions worsened considerably. So he is a bit thinner but not terribly noticeable. (Largely because he often harassed Watanuki on Lacerta for meals :x)

One very important thing to note is that he has terrible scars on his back. This was the result of the Judge King's lightning barely missing him as he escaped Sabra. They are healed, of course, but as burns go, it's clearly not the most comfortable.

Memories
The whole point of Sabra is that people willingly gave up their memories so they could play games, regain them by winning, and eventually win the ultimate prize of a wish. For Ophiuchus, the Judges' team, the way to earn memories by the time Pecha came around was to assign missions and turn in the results. Pecha wasn't lazy about missions, but they were mostly trades more than anything else. He was also not in a rush to regain his memories, so he only regained 5. Total.

Memories regained:
1st→ Shinra patching him up/taunting Shizu-chan (pc)
2nd→ Meeting Sonohara Anri/declaring war on Saika #
3rd→ Russian/English/other languages *
4th→ Shizu-chan at his Shinjuku apartment :/ #
5th→ Twin little sisters lolol they try too hard (pc/nov) *

# denoted skill gained
* denoted general info-dump
pc denoted pre-anime start canon
nov denoted info only found in novels

Update: Pecha has recovered all of his memories when Messenger, still hopped up on King's Power, gave back his name Orihara Izaya.

Pecha does still have memories of Old Sabra. Specifically, that of a Priest from Lacerta named Isaiah. This is because of a thing the Judge Surgeon pulled so blanks could properly understand the reason for Sabra La Tau's current system and possible methods to end it. These memories are faint and aren't very cohesive, but Pecha does draw a lot of his knowledge of the Judges and Sabra in general from them.