The supporting character's harem is very normal - Chapter 364 Lathel, you are really interesting

In each world, there would be the ultimate blackened female lead called Lin Xia, and each of them would’ve drowned in the light of their first love, aka the moonlight. Unsurprisingly, all of these moonlights were beautiful, attracting the love and adoration of Lin Xia, but in each and every world, the moonlight would eventually leave in the end, ultimately causing the blackening of Lin Xia’s fragile heart.

Years later, when the blackened Lin Xia finally fell for another woman, the special memories of the moonlight which was buried deep within her blackened heart began to fade, replaced by the light of the true soulmate.

And when the memories of the moonlight faded to almost nothing, the moonlight returned abruptly, only to be rejected by the moved-on Lin Xia. Filled with a crazed sense of jealousy, the moonlight began to destroy the new couples’ lives, only to be hated entirely and finally, crushed cruelly by the angered female lead.

And this is where the story begins, as a world-hopper, Ye SangSang would complete her missions in these worlds.

- Description from Novelupdates

A firefighter in her previous life, Li Jing’er transmigrated back to ancient times and became the wife of the second son of a farmer. A month after Li Jing’er married into the family, her husband left to join the army.

Then news arrived that her husband was killed in battle but the compensation paid by the imperial court was snatched away by her greedy in-laws. Forced into a corner, she planned an escape, severed family ties, and left with her six-month-old baby daughter.

Joining the flow of refugees escaping from disaster and war, she picked up several lost and abandoned children along the way and tried to start a new life.

Then out of the blue, her deceased husband appeared…

- Description from Novelupdates

What if a wisp, with zero EQ about human culture and habits, gains the opportunity to cultivate and finally achieve human form? Now he can enter cities, experience technology, and fight his way to the top, right? In this universe where wisps are seen as nothing more than cultivation resources, a wisp stands up to challenge the wisps destiny! Not without causing a lot of misunderstandings on his way, of course…

A series of short stories in the world of Toaru Majutsu no Index organized into chapters featuring Kanzaki Kaori as the protagonist, going around the world and space doing missions for the Church of Necessary Evil, however, there is more than meets the eye as each incident is connected.

One chapter was bundled with each limited edition release of the Toaru Kagaku no Railgun anime DVD and BDs, with all of them together being equivalent to a single normal Toaru Majutsu no Index volume