Harry's POV:
Percy quickly became close to many people within the order and with his and Sirius obsessive support of the kids joining the order he gained the favor of all the kids who were feeling left out. Percy went on stating things like "If they don't join I'll just tell them everything I know" or "I have been in there shoes and it only put me in more danger."
However, over time it became increasingly apparent that Percy was not human. Instances like when Percy encountered the boggart and instead of it manifesting a fear, briefly showing a dead blonde wearing a necklace with beads on it and a ring surrounded by a hellish wasteland, it flickered then screamed before fleeing. Percy was cold for hours after that and caused terror to seep into everyone's minds whenever he would walk into the room. Other instances were when he did things that shouldn't be possible like when he ripped the severed heads of house elf's and the painting of Sirius's mother off the walls claiming "I won't have these grotesque abominations of art in a building I have to spend a significant amount of time in." Which gave us all wipe lash when he immediately smiled saying something about an Annabeth rubbing off on him.
The biggest times, however, where not when he was sparring, Mrs. Weasley shot down that idea after Percy accidentally broke one of the twins arm, or when he was angry but when he would stare off into space sometimes for hours. It was as if he wasn't even there but instead sucked into a memory. Or when something would spook him causing him to have his blade out within a fraction of a second. The few times a vulnerability that were fleeting and rare but showed just how much Percy has gone through. There was intense sadness, pain, regret, and fear underneath the layers of pleasant smiles and snarky attitude. We all concluded over time.
Percy Jackson was broken, and it terrified us. What could break a man that laughed at Voldemort's name? Frequently mocks the death eaters without fear and seems to have sea of power flowing out from him? The few stories he tells about his past only add fuel to the fire. They usually being normal stories about him and his friends on quirky adventures. That is until you start asking questions and then you realize why he crashed his own funeral. Or why he was at the Hoover Dam among many other stories he told. It even shows through at meetings when he displays an insane level of cunning, personal experience and cold hard wrath that causes him to have a blatant lack of empathy for any followers of Voldemort.
Despite all this Percy became fast friends with the twins, Sirius, and a couple of other order members along with becoming a mentor for Harry. Quickly spotting how alienated he felt from Dumbledore and his friends.
"Harry, can I talk to you for a moment? I'm going to head back to California for the night soon and I wanted to talk to you before I go." Percy asked Harry one night.
"Sure Percy. What do you need." Harry asked, clearly confused to why he was having a sudden meeting with Percy.
"You are miserable Harry. You have survivors guilt regarding to Cederic, you feel alienated from your friends and Dumbledore. Then to top it all off you are attempting to put the weight and responsibility of the entire war on your shoulders." Percy told Harry without a hint of question in his voice.
"I-I. Wha… What?" Harry asked, clearly shocked at how well Percy called him out.
"It is normal to feel the way you are feeling. You are a teen, nothing more and nothing less. You should not have ever been expected to fight against Voldemort, just as you should not have ever been required to fight against a Basilisk, nor free an innocent prisoner. You saw something that would break most kids your age and barely been given the chance to mentally recover from it. You are a victim not the one responsible. At the end of the day, you had no way of knowing he would die, and you had no way of stopping it. His death was pointless one that marks horrors of war. But at the same by some cruel twist of fate and wrong place at the wrong time you ended up being the hero and while it isn't fair you can't take it out on others. Trust your friends because your life is now a do or die situation and cannot afford to be angry at your friends. So, pick yourself up because you are the hero whether you like it our not." Percy told harry in a serious tone that showed he was speaking from experience. Before turning to leave the room, he said in a soft barely audible whisper "I don't know why Dumbledore is treating you this way but I'm going to figure it out. You need to trust him until you get the full information because he is leading this war against Voldemort, and it can be dangerous to walk alone." Which only left a very confused Harry that now had a lot to digest.
Percy disappeared a couple of days later, much to the shock of the order, and only left a note explaining his absence. It was extremely hard to read and barely legible with its horrendous spelling, grammar, and punctuation. Not even getting started on the fact that randomly the letter will switch between English and a language none of us were capable of recognizing. After a couple of hours of intense study undertaken by Professor McGonagall, we were able to make out what the letter said, apart from the non-English parts, which sums up to Percy going back to camp, something about a quest, and would be on the train going to Hogwarts to complete his grounds keeping duties. Once off the train he will relieve Hagrid's current replacement.
Percy POV:
Percy had no idea why the wizards had to make everything so overtly convoluted. Why did they insist on putting the entrance to the train, that is the only way to Hogwarts, on a random wall and not telling anyone about it. Luckly Annabeth, knowing Percy, insisted on him going several hours early just in case. Slipping in just as the entrance closed behind him was not ideal but was to be expected with his life. Making his way onto the train he could feel the stares from everyone. For some reason, the wizards seem to be skittish of him. Pulling off his best smile he attempted to lighten up the room, which kind of succeeded. A couple of minutes looking for a room that was empty he finally found Harry and his friends in one with just enough room for one more person. As he made his way into the compartment, he eyed the skinny, emerald eyed boy who was clearly abused at home. Especially if you account for the oversized clothes, skinny frame, and rocky mental health. This angered Percy and when he found out Dumbledore knew it caused him to fight with the old headmaster about it. Apparently, it was for his own protection something about 'love of a mother' which to Percy was Bullshit. No child should be subjected to that life and there were other options, so Percy made a vow to never force that kid to go back with that revolting family. He also may or may not have pulled some strings so it may not be safe to go back there anyway.
"Percy! You're here! Ron and Hermione are somewhere else doing prefect duties." Harry greeted me with some slight bitterness at the last part. Harry was jealous of them.
"Harry it's good to see you too! It's exciting to hear about Hermione and Ron's new responsibilities. You would also have been a good candidate but I'm glad Dumbledore understands the stress your under with Voldemort and all" I made sure to stress the parts about responsibility and stress to try to get him to understand why I assumed Dumbledore didn't choose him. It seemed to work as Harry got the message behind my words. His shoulders seemed to relax at hearing my proposed explanation.
Noticing the other kids in the compartment I asked Harry "Who are your friends?"
"Neville" said a slightly pudgy boy in a shacky voice.
"Luna, did you know you have a lot of Nargles and Workinshire Sprouts swirling around your head?" the blond haired witch with eccentric glasses and a magazine that was clearly upside down.
"Oh, really?" I asked as I raised my eyebrow playing along.
"You might want to seek therapy because the Workinshire Sprouts feed off of negative energy." Luna said in a board this-is-fact tone.
That checks out. If demigods are good at anything it is collecting trauma like trading cards. "I'll definitely consider that." I responded back with a smile.