Years ago, Rick Remender did a Punisher run for Marvel Comics even though he admitted that he never was a fan of him nor did he read any of The Punisher comic books at all. If he wasn't a fan of The Punisher, then why did he agree to do a Punisher run in the first place? Anyway, some of the stories he made were really good, but others didn't cut it. And the worst thing Rick did to Punisher during his run is turned him into a Frankenstein monster whom he calls, "Franken Castle" which didn't sit well with a huge majority of Punisher fans everywhere. It began in the Dark Reign storyline when Daken, the illegitimate son of Wolverine, sliced and diced Frank into many pieces. Then, what's left of Frank was salvaged and converted into a Frankenstein monster by Morbius who brought him back to life as the monstrous Franken Castle.
A vast majority of Punisher fans didn't like it and made a big spiel over it until Remender finally gave in and turned Punisher back to his normal human self using the Bloodstone.
I admit that Franken Castle is a very likeable character. In my opinion, he should have been a separate character from the Prime version of Punisher to begin with. Turns out that there are two different Marvel realities (Earth-666 and Earth-BW20D) that both featured Franken Castle as a separate character from the Prime version of Punisher. In such worlds, both alternative versions of Franken Castle shared the same fate as the main Punisher when they were once human, but was killed and chopped into many pieces before they were salvaged, reassembled, and reborn as Franken Castle and stayed that way ever since unlike the main Punisher who was reverted back into human form by the Bloodstone.
My version of Franken Castle, on the other hand, wasn't a victim of Daken's chopping claws. In fact, he was once a human being as The Punisher, who was riding his Battle Van in a foggy forest while waging war against a criminal mob escaping from him when he suddenly got ambushed by a large Hydra tank that suddenly appeared without warning. It bumped him into a large tree and crushed him along with his battle van. Punisher never got a chance to escape. He was gravely injured, barely alive. His body suffering 70-80% in damage. His heart beat faintly. He would've been a goner if it weren't for Man-Thing who saw what happened and salvaged him from the wreak right after he destroyed the Hydra tank. He then took poor Frank to Morbius' castle where Frank was reassembled and brought back to life as Franken Castle to help The Legion of Monsters battle an evil force that's threatening to kill them. Later as Franken was exploring the castle, he began to feel the need to play music, which is something that was thankfully kept intact while the other parts of Frank ended up getting crushed into many pieces by the Hydra tank. He was shown to the parlor room where there was a grand piano and a violin standing in front of a large window. But Frank didn't want to play the piano. He didn't want to play the violin either.
Morbius: "Well, what do you want to play, Frank?"
Franken Castle: "This!"
Franken smashes the piano and takes out its wire frame which he converts into a harp and plays a strange but a very sweet medley on it that moved Morbius, Man-Thing, and rest of The Legion of Monsters to tears.
And here's the newest Punisher fan art piece I made of Franken Castle on his make-shift piano harp.