Blood Covenant

Blood Covenant is a vertical fantasy series shot in 9:16, so it fills your phone screen the way it was meant to. It runs 30 episodes of roughly one to two minutes each — about 45 min in total, easy to finish over a few commutes. The plot, in short:

After a war defeat, Cecil—the fake vampire prince swapped at birth with a heart ailment—is betrayed by his lover Rain and the true prince Leon, then cast down as a slave. On a snowy night he stumbles upon Cain, the human emperor, and discovers intimate touch heals his heart. Cain shields Cecil; they strike a bargain. Leon's schemes backfire; stripped of rank, he falls. Cain dissolves his engagement; Cecil, restored to his princely identity, marries Cain. The two stay together for good.