Staged in the MCU everyone has Soulmates. On their 18th birthday they start experiencing their soulmates pain and sometimes get scars. Soulmate life expectancy stretches across the bond, not aging beyond 25 till they meet their match. It’s rare for people to have more than one soulmate but not impossible. Steve and Bucky are soulmates, both sharing scars from years of survival together. Saved from Hydra control by Steve. Going through recovery at Avengers tower.