Keith doesn't find out for a while. It slips his mind briefly when Shiro disappears. He doesn't have the time to think about it. Not when he's trying to find his brother.
He's reminded after Black chooses him.
"I can't be the leader. I- I'm not-"
"Keith," Lance says. He puts his hand on Keith's shoulder. It's comforting, distracting him from his tears enough that he doesn't immediately start to cry.
Keith looks up at Lance and into his eyes. They were brown this time. A deep, rich brown, like the earth after rain, with flecks of gold in them. Keith thinks that he likes Lance's eyes when they're brown, not blue.
"The black lion has chosen you to be its Paladin. I respect it's choice, and you should too," Lance tells him. Keith nods, unable to say anything because he truly thinks that he'll cry.
Keith can feel Red and Black in his mind. Black is much calmer than Red, who often burned like fire did.
She was saying goodbye, that she enjoyed having him as her Paladin but that he was truly meant to be Black's Paladin instead. Red's fire slowly disappeared, leaving him with Black, who pressed comfort into his mind.
Everyone separates after they congratulate Keith on the promotion, each person going to do what they need to do. Keith goes to the training deck, needing something to keep him occupied.
He takes down bot after bot, not caring about how long it's been, loosing himself in the comfort of being able to take out his frustration and anger on something that wasn't alive, but that he could still cut down without mercy.
Shiro wasn't there to stop him, to remind him to take care of himself, so he continued to train.
"End simulation." The program obeyed the voice. Keith turned to glare at the person who had cut his training short, only to be met with Lance standing there, arms crossed and eyebrows raised.
"What do you want, Lance?" He asked. Lance was silent for a few ticks.
"You need to take a break," he simply said when he did speak. Keith rolled his eyes.
"As if I need you to mother hen me," Keith snapped. Lance just sighed.
"Your movements have been getting slower, so has your reaction time," he pointed out.
"So, knowing you, you've been training non-stop for hours without a break, and I now have to drag you out of here kicking and screaming, so that you can shower and eat." Keith scowled.
"I'm fine," he insisted. When was Lance so observant of him?
"Please, Keith. You're our leader, now, you need to be well rested so that you can carry out leader duties," Lace reasoned. Keith's Bayard changed from a sword to its simplest form.
"I never asked to be the leader. I can't... I can't lead you guys like Shiro," he said. The admission had him turning away from Lance, staring at the floor. He hadn't meant to tell Lance that, but there was something about Lance that made Keith feel comfortable enough to open up to him.
"Keith," Lance said. A hand came to rest on his back, gentle and comforting. "The point isn't to be a leader like Shiro was. The point is to step up and fill your role, even if you don't want it. Black chose you. If she didn't think that you could lead us, then she would have chosen someone else, like Allura."
"I just... This is the second time, Lance. The second time I've lost my brother. I- my mom left me when I was a baby, and then my dad died and I was left alone in the fucking foster system, then I met Shiro and he decided to give me a chance, and then I lost him when he left for Kerberos and- it hurts." The last two words were quiet. Keith realised bleakly that there were tears on his face.
Lance pulled him in for a hug.
Keith held onto him like he was his lifeline, the only thing keeping him tethered in the endless expanse of space.
"Pidge knows how you feel," Lance reminded him when he'd calmed down enough. Keith just nodded.
He left the training room behind. When he showered, he just stood there, under the water, feeling numb while Black pressed comfort into his mind. He went through the motions as if he were a robot, washing his hair, his body, and then stepping out and drying himself and getting dressed.
He didn't have anything to do, so he just... Walked. He didn't have anywhere he needed to be, so he just walked.
He ended up finding Pidge sitting in Green's hangar, typing away on something.
"Hey, Keith," she replied. She continued to do whatever it was she was doing.
"Go ahead, as long as you're not going to annoy me like Lance does." Keith gave a small smile at that and sat on the floor near Pidge. They were silent for a while. "It sucks, doesn't it?" She asked randomly.
"Shiro," came the reply. Easy and simple. Keith nodded.
"Yeah. He's... He's my brother, and this is the second time I've lost him," he told her. Pidge stood up and sat on the floor with Keith, resting her head on his shoulder. Keith rested his head on hers.
"It sucks so, so much. I just- I just want to find them. Matt and Dad." Keith understood what Lance was getting at earlier.
Go talk to someone who knows your pain, who can sympathize with you.
Keith wrapped an arm around the youngest of the group and hugged her.
"We'll find them. All of them. Shiro, Matt, your dad. We'll find them, we'll bring peace to the universe, and then we can go home and just live our lives," Keith said.
"I hope you're right." Pidge curled up further into Keith's side.