The Teenage Mutant Ninja Turtles have seen their lives go in some incredible directions over the years. However, none of those has hinted at a future as bleak as that seen in The Last Ronin. Published by IDW in 2020, The Last Ronin was a five-issue miniseries written by TMNT creators Kevin Eastman and Peter Laird, with Tom Waltz and Andy Kuhn with art by Ben Bates and Andy Kuhn. The miniseries was so well-received, it spawned a second five issue miniseries, Teenage Mutant Ninja Turtles: The Last Ronin -The Lost Years that released in 2023.
Source:https://www.cbr.com/tmnt-last-ronin-turtle-deaths/