Author's Notes: I had always been interested to write ReiBert in a Patrochilles AU. The Song of Achilles definitely had (and continues to have) a chokehold on me ;v;

In this AU, Reiner is Achilles (let's pretend for a sec that his father loved him asdjklfjlk), and Bert is Patroclus. In terms of setting, it is set when Bertholdt was first designated as Reiner's chosen companion (pre-Trojan war).

This was a quick drabble written for a Discord gift-exchange event! I hope you enjoy the read!

"My eye catches on a light head among dozens of dark, tousled crowns. I lean forward to see. Hair lit like honey in the sun, and within it, glints of gold—the circlet of a prince." – The Song of Achilles

With the bright Spartan sun glaring from above, a young teenaged Bertholdt wiped the sweat off his brow.

Only another 25 push-ups to go. You can do this , he thought to himself resolutely. Given his circumstances, he had no choice but to be resolute.

The Oracle, Ymir, had prophesied that there was going to be a war to end all wars in the horizon. To this, King Braun, in his frailty and old age, decided to adopt all the orphans in the surrounding territories for the purpose of establishing a youth army in his name. By the time the supposed war would break out, the street urchins he picked up would have grown into fit and able warriors, ready to defend their adoptive homeland against any and all sorts of enemies.

Around Bertholdt in the dusty castle grounds, the other orphan boys were carrying out their workouts with much gusto. Bertholdt knew that he had to keep up with their youthful vigor if he wanted to earn his keep in the Brauns' castle.

Eren and Jean had made their requisite push-up exercise into a competition, goading each other as they completed their required reps with haste. The names they called each other – horseface, suicidal maniac – had become commonplace among the trainees. Connie, Thomas, Armin, and Floch stood on the sidelines – cheering them on in amusement. Were they already done with their reps? Bertholdt wondered.

Bertholdt was by no means physically unfit, but his propensity to overthink and get lost in his head tended to make him hesitate when he was supposed to act – according to Shadis, that had decidedly been his weakness as a warrior.

"You need to be more decisive with your strikes!" Shadis had once censured him. "Your form is good, but you are holding back – and that makes a world of a difference when you are faced against a lethal enemy."

Bertholdt had remembered looking at the ground and nodding, only for Shadis to pull him out of his reverie by tilting his chin up.

"What is most dear to you, Bertholdt? What would you do if you were at risk of losing it?"

Intuitively, Bertholdt knew that his instructor was trying his best to motivate him – though he wasn't sure if the older man's efforts were in vain.

After being evicted from his own father's kingdom after accidentally murdering another boy, Bertholdt felt that he had nothing worthwhile to live for. He was grateful to King Braun for giving him shelter and his daily bread, sure, but he found it difficult to envisage a future he wanted to live in. If he did not awaken from the night's slumber the following day, it would not have been much of a loss to society, he felt.

"Hoover!" Shadis' call woke Bertholdt out of his musings.

"S-sorry, sir, I'll finish my push-ups now."

"No need. Follow me."

Bertholdt felt the eyes of the other boys on him as Shadis singled him out and led him inside the castle.

"What are you brats looking at? Get back to your exercises!"

"Yessir!" they chorused, scampering back into their formations.

Bertholdt felt a weird combination of foreboding and calm as he walked behind Shadis. After they climbed three flights of stairs, Bertholdt was starting to notice that he was in a part of the castle he had never been to before.

"D-did I do something wrong, Sir?"

Shadis chuckled under his breath as he brought the lanky teen around the royal family's wing.

"Far from it, my boy. It looks like your luck's about to change from here on out."

Reaching their destination, Shadis knocked on the door in the furthest corner of the wing.

"He's here, my liege."

"Bring him in," the voice from inside declared authoritatively.

As Shadis opened the door, Bertholdt's gaze immediately fell on the sole figure inside – Prince Reiner. His golden hair shone brighter than the sun, handsomely framing his defined features.

The prince rarely made his appearance in front of the other boys, but Bertholdt remembered always losing his breath whenever Reiner entered a room. His radiant beauty was certainly evidence of his rumored goddess mother's blood coursing through his veins. His chiseled cheekbones, toned muscles, and radiant smile – Bertholdt had never felt more out of place in front of such greatness.

"You," Reiner said simply, his golden eyes looking directly at Bertholdt's olive-green ones, "will be living here from now on. You will be my chosen companion, my brother-in-arms. We will train together, eat together, sleep together."

He paused a bit to give the other boy a chance to respond, but as Bertholdt remained speechless, Reiner continued, "Shadis, Bertholdt's bed and personal items can be brought here?"

"It will be arranged before sundown, my liege."

"Excellent," Reiner grinned.

Finding his voice, Bertholdt croaked, "I-I am honored, my liege, but, are you certain? Surely, you know of my past – that I have once killed a man, that I have blood on my hands?"

While princes often sparred with the rest of their troops regularly, they also had an inner circle with whom they received special training – not only about fighting and military knowledge but also about culture, the arts, and politics – things that princes needed to know in times of peace and war.

"Surely, I would only cause a stain to your good name, sire? My father has exiled me – I have no worth or value to offer you."

Despite Bertholdt's evident distress, Reiner looked at him bemusedly. He walked forward and held Bertholdt's forearm reassuringly.

"You sure are an interesting one," Reiner said matter-of-factly, mirth bubbling in his voice. "I do not mean any offense by this, but I am the crown prince of these lands. Godly blood runs in my veins. Nothing else – nobody else – can advance nor mar my reputation."

"Have faith in your standing, in who you are, my dear Bertholdt."

Bertholdt felt his cheeks warm involuntarily at the prince's attention.

"O-okay, sire, I will do my best."

"Now come, we need to tell my father about this."

With Bertholdt's hand held tightly in his, Reiner led them to his father's chambers.