Both are about Deity-like figures who fall in love with the reincarnation of their former lovers. In Destiny's Love the deity-figure is part of an organization who governs Earth while in King of Blaze the deity-figure is more of a refugee from another planet. Yes, both "deities" are actually aliens.

Both are about an alien who was left behind a long, long time ago on Earth. In My Classmate from Far Far Away, this alien is the female lead while in You Who Came from the Stars it's the male lead. The setting is very different, with YWCFTS being about the adult world while MYCFFFA primarily focuses on the student life aspect and has an overall more youthful vibe. Both equally amazing dramas!

Both contain characters cursed with immortality. The gods have physical incarnations (Or one at least in Long For U 2). There is a "reaper-like" character in both dramas as well as a goblin character (They're both the same person in Long For U 2). Overall, both similarly enjoyable!

Both have characters stuck in a game. Both also have the protagonist find love in the game. Though, Your Highness seems to use more CGI special effects and really plays off the super powers aspect.

Both have an alien male protagonist in love with the reincarnation of a past lover. Both modern fantasy romances. The Love Knot is has a little more tragic ending but both still executed this type of genre pretty decently.

Similar concepts where a king travels to the present. Though the king in My Assassin Girlfriend seems to be more intelligent when it comes to navigating the modern world.

Similar vibes and concept. A king traveled to the present. My Assassin Girlfriend seems to focus on less characters so the plot may be easier to follow.

The prequel to this so obviously a must watch. I think it's best to watch in order. This time, more ppl come over from the past

Both have a similar vibe though The Eternal Love definitely has more slapstick comedy. Traveling to an ancient world? Check. Ancient man adapting to modern society? Check. Honestly both equally amazing dramas to watch.

Both dramas have a king who travels to the present and later also to the past. Both romantic comedies.

Both dramas have the female lead travel to an ancient parallel universe. I think the vibes of the two dramas are also similar. The female leads also have a bubbly character (Though Xiao Tan is definitely more sassy) and the male leads are portrayed more cold on the outside but warm on the inside.

Both dramas have characters who time-travel to the past. The difference is that in Somehow 18, the main character had a purpose for time-traveling and in Love, Timeless the time-travel is an accident that the main character happily accepted.