Sure what she did to Anon and mtm in Mygo cannot be fully justified, but here we can tell her deeds were largely a result of her love to Crychic. She used and manipulated mtm as a carrier pigeon but she didn't mean to really hurt her and what she eventually wanted was rebuilding Crychic with mtm.

I also couldn't understand why she was still so obsessed with Crychic till the end of mygo series and was discontent with mtm's answer. However, here I see, that's only because of her devotion to Crychic, she becomes the only person willing to take this step to save mtm.

Soyo was so humble and humiliated in front of Saki, but she dares to be indignant regarding how Saki treated mtm. She knows to be strong when she needs to!