Path Forger

Ever since the appearance of superpower users, war has not stopped on Earth. Sentinel Han Tae-young and Guide Joo Se-in have been paired up in the military, keeping in sync for five years. Then one day, Tae-young suffers a runaway berserk episode, and Se-in finally realizes that Tae-young has been manipulating their pairing, shaving off five years of his own lifespan just to stay by his side. (Source: Lezhin, translated)

Original Webtoon:
Lezhin