I felt sorry for Mazurka after she was disposed of just like that when Deathmark and Deathgiller planned to use her as a bomb to destroy the Goggle V's secret base.
I felt sorry for Megiddo because of how his father treated him. Seriously, his dad is a jerkass and I felt it was really karmic for Aton to fall at his son's hands.
I felt sorry for Monster when he saw Juuoh die before his very eyes. Their bond was so close.
I began to feel pity for Dr. Man when I saw how much his son Junichi still loves him. In the end, I thought his death was pretty sad. He had more humanity imo than his extremely sadistic underling Mason ever had.
Yamimaru and Kirika- Compared to the three deceased generals, they had more human qualities considering they were also half-human. Yamimaru was mistreated by Zulten in the past. Kirika was a reject in her school. These two villains aren't so bad after all and good they had a second chance in life.
I felt sorry for Shiima, Bubba and even the extremely cruel Ahames. Shiima was brainwashed to become evil, Bubba was forced into service and Ahames never got her planet back.
I felt sorry for Kaura after he decided to reveal the Flashmen's parentage and went against Lee Keflen.
I felt sorry for Igam due to her being misguided by Zeba and having to hide her secret only the audience knows. I did also feel sorry for Baraba as he saw his mother blown to bits and even in the part where Kiros deceived him. Fuumin's undying loyalty to Igamu was also worth praising too.
In Liveman I did feel sorry for Dr. Mazenda and much earlier Dr. Obular (who became a priest). Dr. Mazenda's death with her former humanity was just touching.
Okay call me insane all you want but there were times I felt pity for Radiguet for a few couple of times that is until he resumes back to being the ever bloodthirsty insane villain we all love to hate. When were these times I felt sorry for his genocidal maniac of ever-growing insanity who knows what he'll do next? One was when Juuza turned him into a human where he fell in love with a girl and two, when Tranza came to power and bullied him too frequently (and yep, I was glad that he got even with Tranza). Aside from that, he's hateful all throughout especially how he treats Maria like trash, even if he did have feelings for her.
It does suck to be Maria. Devoid of memories of who she is, Radiguet developed a somewhat lustful fancy on her and it was even worse that he always forced her back to him. It got worse when Radiguet further corrupted her and even literally monsterized her so she can be more "worthy" to rule by his side. In the end, she even refused Ryu's love any longer because she knew all the bad she did while she was Maria. It was a truly sad scene.
Gure was far more humane than most of his fellow Vyram members. He soon had a relationship with Maria and he was more than willing to let her go if it made her happy. When Radiguet turned Maria into a monster, I could pity his situation too. It was also a sad scene to see Maria die which led him to pursue his final battle with Gai Yuki in which he nearly prevailed. His death imo was just sad, he fought Gai Yuki so he could die a warrior's death.
Akomaru- I felt sorry for him because he was mistreated by his father and he later realized he was being loved by his mother.
Queen Hysteria's act of blowing herself up to save her grandson proved that she wasn't as evil as we thought she was. In fact, Momo was saddened by her death.
Carranger may have been a funny season but I felt it wasn't funny at all when the Bowzock crew members were betrayed by their master Emperor Exhaus. Zelmonda's act of helping the Carrangers in the final battle was in fact very appropriate. They did finally reform to tell the tale.
Dr. Hinelar's backstory of losing his daughter made me feel sorry for him (for awhile) until he went completely insane.
I felt sorry for Venus with how she died. She died giving her life force for her sibling Zylpheeza.
Don Dolnero though he was a villain, he did care for his subordinates. In fact, it was nice to know he did care for Gien after all who was soon growing insane too. Gien's ever growing insanity was more pitiful than annoying to watch too because when he turned genocidal, he was still perfectly aware of his actions.
Shizuka though she's a nuisance to the Boukengers was soon worth pitying together with her master Gekkou when Yaiba betrayed them. I really considered Yaiba despicable for mortally wounding her near death.
Rio and Mele- They were more of anti-heroes than villains in Gekiranger which was evidenced by their towards the end scenarios and later appearances. They were both manipulated by Long.
Kitadanes and Kegalaisha both were treated like trash by their master. I found their death imo quite powerful for a series that gets bashed for its lower quality.
Any more you want to add? Let me know!