This is an event that is a collaboration between the anime Puella Magi Madoka Magica and the video game Battle Cats, the event hasn’t happened since 2019. The event will last from November 8 till November 22, the units in this event are: Madoka Kaname (Uber Rare), Homura Akemi (Uber Rare), Sayaka Miki (Uber), Mami Tomoe (Uber), Kyoko Sakura (Uber), Bebe (Uber), Kyubey (Super Rare), Madoka Cat (Rare), Homura Cat (Rare), Sayaka Cat (Rare), Mami Cat (Rare), Kyoko Cat (Rare), and the stage reward units Li’l Madoka (Rare) and Li’l Homura (Special) and finally Kyubey Cat (Rare). Many of the original events and some units have been retuned. For example, the Ubers Homura Akemi got immunity to slow, Sayaka Miki gained immunity to knockback, and Kyoko Sakura got immunity to knockback. Day 4 onwards you can get the true form of Li’l Madoka from defeating the Walpurgisnacht witch, you can get Li’l Madoka from “Be a Magical Girl”. You can get Kyubey cat from “Be a Magical Girl 2, you can cat Li’l Homura for free as a stamp reward. The Ubers and Li’l Madoka and Li’l Homura have a special  ability that allows them to take out special bosses: witches. In fact, if you put both Li’l Madoka and Li’l Homura in the first row you get a massive boost to this “Witch Killer” ability.

The game cannot be downloaded on computers without emulators, but is available on the app store for phones and I-Pads

Sources: https://www.youtube.com/watch?v=qT2xkHoLtD8