Shiinaecchigawarubyhoshinothefullanimat: 2021

Shiina Emerald and Ruby Rose are characters from the RWBY series. Hoshino might refer to Aya Hoshino, the creator of the series. "The Fullanimat" could be a typo or mix-up. There's no official project called "The Full Amination" for 2021. Maybe they're referring to a fan-made project or a fan event? Also, 2021 was a year when RWBY released new content, like Episode 9 of Volume 7. Maybe the user saw a fan project or mod that combined RWBY with other anime?