I have a character called Warp. But the only reason she could be dubbed as 'insane', is due to her background. I chose to have her as an Army type of Wolf. You know, used for the real rough parts of war, shootings, sniffers, bombs and such. She's saved plenty, gotten shot once in the leg, a limp now there. But she uses it to her advantage in a way. Because she grew up being part of the Army(not the UK, or the USA, or anything like that. An army in a small town, that was given a bad name by others because they do not ship their goods to other countries.) She's seen death so many times, and torture. Warp isn't her real name, infact, due to all her memories and the things she's seen, she forgot her own name and the town calls her Warp. She, like you said above in your post, has goals. She doesn't kill for the sake of killing. She preys upon others(animals, humans etc), that treat others horribly, torture, abuse etc. In her mind, ridding the world of those, would make it a better place. In HER mind, she's doing a good thing, even if others see it as it's a bad way. o~o
So yeah. She has goals, she has motives. o~o
I agree considerably towards this post though. I see plenty of just..RAOIHSKUHGKDFGHD RAAAAH -Kills- xD