Im jumping on the lacelot bandwagon for a bit here but its more just lance centric.
So imagine lance meeting or perhaps getting kidnapped by lotor (obviously) and Lotor being nice to him and stuff, complimenting him, “Such a shame the others don’t realize the heart of the universe pilots the blue lion.” and just going on about how lance is special in one way or another. And at first Lance isnt stupid, he barks back things like “shut up, they know im special” or “i AM important to them.” etc. Even thougg he feels as if he’s lying a little in the back of his mind because he isnt sure if they even appreciate him. And so after countless times of arguing back Lotor decides to let Lance go but before he does he says “dont worry blue paladin, if you change your mind i will be here waiting for you to return so you dont have to live in their shadows anymore. I’ll make to give you all the love and appreciation you deserve when you arrive.” and that kind of makes lance think for a bit before he takes off to the castle ship.
Fast forward, he gets there and the first thing he hears is Keith yelling at him for disappearing in the midst of battle and a lecture from Shiro about why he needs to be more carful and alert. Hunk and pidge ask what happened to him. Lance is hurt that no one realized he was kidnapped after screaming into his mic for a minute or two before being silenced. Lance contemplates whether he should tell them about lotor but decides not to. He then gets called by allura who tells him to be more carful out in missions and that mistakes are crucial at the time and that he must try harder to be with the team. After that, he tries to help the team when they’re doing something. After another mission and another failed attempt to get his word into shiro, thay night he starts contemplating what Lotor had said to him before he was let go. After another few weeks of things as usual for him, his last straw was when Shiro told him to “stop being childish Lance, that plan might not work.” which was followed by silent stares. He ended up snapping at everyone. Which goes a bit like :
“OH IM THE ONE BEING CHILDISH?!? YOU NEVER LISTEN TO ME IN THE FIRST PLACE ANYWAYS, IM JUST TRYING TO HELP! LET ME HELP SHIRO!”
“Lance! dont talk to shiro that wa-”
“SHUT UP, JUST SHUT UP ALREADY KEITH, MR PERFECT PILOT, YOU DONT KNOW WHAT ITS LIKE TOBE IGNORED BY SHIRO SINCE HE’S ALWAYS LISTENING TO YOU! YOU DONT KNOW WHAT ITS LIKE TO TRY YOUR HARDEST ONLY TO BE SHUT DOWN BECAUSE NO ONE TAKES YOU SERIOUSLY! ”
“Woah okay dude chill ou-”
“DONT TELL ME TO CHILL OUT HUNK, YOU’RE NOT THE ONE WHO CRIES THEMSELVES TO SLEEP SOMETIMES BECAUSE THEY DON’T HAVE A TALENT LIKE YOU OR THE OTHERS. EVEN PIDGE CAN DO MORE THAN ME!”
And with that he walks out. Later that night he waits till everyones asleep and sneaks out and leaves in Blue, at first he doesn’t know where he wants to go so he just flies aimlessly in space before he stops and opens a wormhole. Once on the other side he spots the galras ship and when he lands in it he is greated by Lotor. With tears in his eyes he looks up at lotor before looking back down and closing them before buring his face in lotors neck. Lotors only words are “Welcome back, Blue Paladin, lets get you all settled in.” before lifting him up and carrying him to his quarters.
After a week without lance Shiro and Allura send a tracking signal for blue and pick it up on lotors ship. They prepare for battle and on the others ship they pick up the signal and track how far they are from them and prepare for battle aswell. Lotor made sure lance had no knowledge of the tracking and battle.
Finally the castle ship arrives and to the paladins surprise when they break into the ship, they are greeted with an armored lotor and galra soldiers and Lance by lotors side, holding him close. As the battle goes on lance manages to help capture the paladins. Allura and Coran manage to escape but lotor knows that they will be back for the others eventually. After they are captured lotor tells his guards to throw lance in there with them. As lance screams “i trusted you! why?” and kicks, lotor just grabs him by his face while hes being retained and says “did you really think i was being serious? Clearly i was only after the capturing of Voltron and its paladins.” to a teary eyed lance before he is dragged away to the cellars. Once thrown in he and the team make immense for now as time is crucial. (They make sure to rebuild their friendship and bonding later on properly) and make a plan to escape. Since Lance has been there longer they ask him how to get out with their lions. After finding the lions and getting ready to escape they find themselves stuck as lotor finds out and tries to stop them. After battling with galra soldiers and lance managing to injure lotor, they manage to escape through a wormhole allura had opened after she recieved their coordinates.
Back at the castle they use lances knowledge of the ship to try and find a way to defeat lotor, and each apologize to lance privately for ignoring him and all the things they did. Especially Keith and Shiro. Allura and Coran included apologized to lance as well. Although it may not solve anything fast, lance is happy that they apologized to him. And with that he knows that they’ll be able to build a stronger bond with time.