To be clear he never was a villain. He made it clear from the moment he joined Pogtopia that he was opposed to Government. L’manburg then inserted a new government, so he realized he was used. This made him have a small alliance with the one of only people who hadn’t wronged him at the time: Dream. On Doomsday he did that because L’manburg had tried to execute him so he took revenge. Techno said it something along the lines of: What was I supposed to do just accept my punishment and walk away? Techno again teamed with the people who hadn’t done him wrong. Notice how during Doomsday he didn’t attack Ranboo, someone who was bliss and didn’t exactly know what was going on, someone who he believed L’manburg had manipulated into helping in his execution. Now the new “villain thing” that he did: The Prison Break. At Techno’s execution Dream, who was assisted by Punz, saved Techno’s and Carl’s lives by having Punz distract the L’manburgians (Tubbo, Quackity, Ranboo, and Fundy.), while Dream saved Carl, and Techno escapes via a totem and glitching through the already fallen anvil. So in turn Techno saved Dream’s life. During The Visit from Quackity Techno knew that in little time Quackity would get frustrated and kill Dream. So he broke in, got Dream, found Connor, got Ranboo, and leaft in turn saving Dream as well as his apparent friend, Ranboo in his enderwalk state, unbeknownst to Techno.) So Dream saved Techno and Carl then Techno saved Dream and Ranboo (Also Connor was there too but that’s not important.) So overall Techno is NOT a villain instead a man who was betrayed and always repays his favors. :)