Some TMNT stuff was always meant for grownups.
Donatello began the Image continuity series by being shot by cyborgs. He survived this though, as he became a cyborg himself, after his body was partially destroyed from being shot and dropped out of a helicopter, with one of the cyborgs which he merged with. He maintained a positive attitude nonetheless, although he was constantly at risk of losing his mind to the cyborg half. The merger was permanent, so Donatello never returned back to his old self during the original Image Comics run.
This stark change meant that the CPU of the cyborg and Donatello often fought for dominance of the body. Donatello also seemed to have become a lot more aggressive, as he shot some kunoichi without batting an eye.
In Urban Legends #25, all the liquid metal was removed from Donnie's body, but he still had a metallic shell while his organic one was regrowing underneath.
- Character Gallery: Donatello
- Appearances of Donatello