Quirk transfers were a thing of the past in Japan. They were banned after the discovery of the misconduct of quirkless to even quirked beings being used and abused for mudain practices, all to either gift a quirk or enhance it.

Doesn't mean those practices stopped. Dr. Kyudai Garaki was one who continued this research through a lab called Star Laboratories and soon enough...the perfect High-End level Nomu was created.

Dr. Garaki: Tomura Shigaraki, allow me to introduce you to 443702.