During the Beast Wars, Blackarachnia was once a Maximal protoform that was captured and reprogramed by Tarantulas but it wasn't until a whirlwind romance with Silverbolt that there was something in this former Predacon that even she herself couldn't see. A vulnerable and very delicate flower that only needed to be nurtured instead of harmed.
Silverbolt tried his best to bring out Blackarachnia's Maximal personality but it wasn't until an experiment to give herself a Transmetal 2 body went a wry and the shell program that Tarantulas had implanted inside her protoform had began to collapse that Blackarachnia began to realize just how vulnerable she was.
Blackarachnia realized that her very existence was threatened by Megatron's megalomania and that if she was to survive Megatron's insane plot she would have to co-operate with the Maximals in anyway possible in a promise that she made to Silverbolt
Blackarachnia's phillosiphy has always been "survival of the fittest!" Upon her arrival back at Cybertron her phillosiphy was tested when Megatron enslaved Cybertron and stole all of the Transformers sparks. Silverbolt and Rhinox were nowhere to be found.
Blackarachnia made a lot of discoveries about herself. Including the fact that Silverbolt helped her to see the light once when there was only dispair. She also realized that she and Silverbolt were like two peas in a staisis pod: he helped her to find herself and she, primus help her, would help him to find himself. The self that helped Blackarachnia.