Nanites
Since Reaps is headcanoned to be made of nanites….he’s able to practically use a small ‘cloud’ of them for anything. Like he can torture people within a few seconds/moments… Practically he just breathes a cloud of nanites into the person’s mouth, they travel to their brain and they fuck them up.
Removing memories, corrupting memories (happy to bad), add memories (torture, war, death, anything that fucks a person up and scars them mentally), replaying the same memory over and over again until the persons driven insane. He can also use this trick to gain information from a target.
It’s…like he can find the host of a person. Like, if this person has had an item for an extremely long time (stuffed toy, necklace, ring, book, etc etc). That item has part of the owner’s soul attached to it. And if the person’s lost it and Reaper finds it… he can “consume” the small bit of soul from the item and see what the owner’s last actions/words were. Like, he sees what they were doing and all the moments before they lost the item. He doesn’t know what to expect whenever he does this. It’s a new vision every time. Most of them aren’t very surprising but some are. He can use this ability to help track down the owner of the item. He uses this many many times when hunting down his enemies…but they’re not out to kill him, his enemies…he needs to continue to eat/consume souls or else his physical body will be no more; he’d be only smoke…or nanites yet he’d still be there in the world…just sort of unseeable only a faint “black wisp” when he moves can you tell he’s there and if you pay attention to those dark corners.
Wraith’s ‘smoke’ or nanite form is neither solid or liquid, but in between. You can push your hand through him and get some resistance but not enough to entirely stop you from having a hand through his chest or something. His lack of form is because of his nanites. They’re moving so quickly that he just loses his solid form. This can be bad. If he’s angry and this happens...well, he becomes a full-body (bodyless?) weapon because of how quickly his nanites move. However, if he’s just excited for sweets or something then the worst you’ll possibly experience from said fast moving nanites is the equivalent of a papercut. He’s sad anytime he hurts someone for simply being excited about something even if it happens rarely because most people tend not to touch him (which is when you’ll likely get hurt unless he’s angry).
“Would he still be able to consume souls while in his Nanite/smoke form?”
He would be able to, yes. It’s just much harder to do considering he’s unable to wield his guns with that type of form to enable him to easily retrieve said soul - shotguns are powerful up close. He can, however, use his ‘new’ form to attack, they are deadly attacks. But, he refuses to just outright kill his current victim(s) – at least sometimes. Considering that his smoke is more of a ‘his skin is dissipating into the air’ if he’s smokey/misty looking…he’s completely harmless. But his nanite-form is deadly. There’s only a 10% chance of his latter ‘form’ to appear because it’s harder to maintain a semi-physical form for more than a minute or two. That’s where he’d have to plan his attacks wisely, only able to form sort of nanite-blades or tentacles if you’d prefer since that’s easier to picture. Since nanites are so small he doesn’t have to put too much effort into killing or harming his victims. They can cut through skin easily or so he thinks. But, in fact, he can wound his victims so quickly and easily because the nanites are continuously moving. Always moving. So because of this movement they’re constantly in, it disrupts the skin - acting very similar to a saw cutting through wood.
“Wait, so say he hasn’t consumed a soul in a while, would consuming a piece from an object help him sustain his form?”
It would, in a way, yes… but it would only be for an extremely short amount of time - a few minutes at most unless the soul was more than a fragment of its owner.
“What if someone’s entire soul went to that item? Oh, would he be able to smell it too?”
In rare cases, he has indeed found some items that had an entire person’s soul to it. Sometimes it’s not even a living person anymore as if the true owner died and it’s soul attached to said item and the item was handed to a new owner; family, friend or a random stranger.
Yes, he can indeed smell souls…or rather the taste since they are no longer part of their host’s body. It’s this particular reason he continues to kill and kill for souls rather than to maintain his physical form - although consuming the souls does, in fact, assist that, too, but he prefers to just taste the souls. The taste of souls is addicting to him, especially those sweet tasting ones that most naïve teenagers carry. Because of this, he doesn’t consume the entire soul sometimes, only taking part and placing the rest inside a safe place - usually a bottle or container of some sort that’s pocketable.
“So, if an entire soul was attached to an item would he be able to see more memories?”
If it’s of a deceased person, yes. He’d be able to see most if not all of that person’s memories. If you’ve seen black butler, he’s practically a shinigami and these souls are their ‘life flashing before their eyes’. He carries a very heavy burden. He remembers and knows everything about all these people yet he’s stable…well, he’s not. He’s not in Talon and he’s killing whenever he needs to or whenever he feels like it. My Gabi is the same, that’s why he turned towards the good side again.
“Has he encountered memories that have nothing to do with his current task/mission but takes the time to do something for them? Like returning an item? Has he ever helped a victim from their captor if they were kidnapped?”
He has, surprisingly, returned a few things. Mostly to children because adults need to take better care of losing their items. Reaper has only helped two kidnapped victims, one a kid and the other a woman - he saved the kid because they reminded him of Jesse, he saved the woman because she reminded him of Angela…but he’ll never admit it to anyone. It’s his little secret.
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Okay, so some of y’all know that Wraith was born from consuming Gabriel’s soul until it eventually killed him, yeah? Well, new headcanon/lore time~!
So, because Wraith was essentially made manifest from consuming Gabriel’s soul albeit accidentally....they’re able to see other people’s souls. Reaps has something similar in the sense of seeing peoples memories via their souls (even if its the tiniest piece of it). However, Wraith’s able to just see what makes up someone’s soul. The good, the bad, the evil, the nasty, whatever you wish to call it. They can easily tell a person’s character this way. This is why in the Triple Threat verse, Wraith wants Reaps around. They see a sliver of - maybe not ‘good’, but something redeemable.