Time For Gien's Insanity
Dolnero shows that he treats the Londarz prisoners like his family. He even went as far as to let the bogus traffic enforcer Arnold (an old friend of his) lose because he was causing strife in the Londarz Family. One plot that's later unveiled is that of him and Gien. Gien wasn't always an android. He was once an illiterate human who helped Dolnero after he was severely wounded. Dolnero repaid the kindness even if he was one of the biggest criminals ever in his era. He even went as far as to have Gien assisted though it pained him to see the person turned into a really clunky-looking robot.
Gien himself has his growing thirst for carnage while Dolnero was obsessed with dominating the crime arena with money. Earlier episodes showed how Gien would just unleash a monster out of insanity (like Mad Blast) just to entertain himself. Later, he would unleash Emboss a diseased alien criminal just to enjoy it. This caused Dolnero to actually come up with a dirty scheme -- first he offered his blood to create the antidote hoping to later make a profit out of it. At the same time, Dolnero himself did show positive traits (or not) by actually caring about Gien. He went as far as to pacify Gien's insanity.
Unfortunately, Captain Ryuya ended up into the present era and pulled out Gien's plug. I dunno what Captain Ryuya was really thinking by doing so, by retaking the Chrono Changer from his ancestor Tatsuya and trying to get rid of the G-Zord. One possible disaster that was foreseen was that Gien's insanity in the present has two outcomes -- him getting destroyed by the G-Zord will cause the 31th Century to disappear while the Great Annihilation would still leave the 31st Century intact. Gien's insanity was somewhat part of history.
Dolnero ended up dying trying to save Gien. Yes, Dolnero thought it'd be best to end Gien's life since the insanity can no longer be fixed. Instead, Dolnero ended up getting severely wounded and dying in the year 2000 causing the year 3000 to shift. In the finale, Gien's insanity where he pilots the Neo-Crisis would cause the catastrophic event. Heck, it even led him to become the final enemy that the Timerangers had to face before they ultimately counter the Lambda-3 in the Neo-Crisis with the Zeta-3 energy. Gien's former personality temporarily emerged before shutting down.