Reji and Scarlet(My another OC) became enemies the moment they saw each other. Like a snake and mongoose.

While Scarlet can heavily damage him with her bullets and blades but her main power i.e. electricity is useless against him.

Why you may ask. That's because he can use his tail like kagune not only for offence but defence too. Using it like a lightning conductor he can easily pass the electricity through him into the ground while being unhurt.