You believed it was over, Genisys' core was destroyed. Gone, last time you heard about it. It was mentioned to be absolutely annihilated and obliterated from the very fabric of existence, itself. The remnants of Team Sonic used multiple nuclear weapons and laser beam weaponry to destroy the entire facility holding Genisys' core.
This hasn't ended. It's just begun..
You stopped, as a 3 foot anthropomorphic amber-orange fox with two tails walked in, it's fur was messy, unkempt and unwashed. Teeth looked as if not taken care of, in literal years. Small tangles visible, it had a white muzzle, white tips of it's amber-orange two tails. Which wagged, it magneta-rhombus shaped eyes with very small bright blue pupils stared. It wore grey-silver trousers, black and grey kneepads. Long white gloves with slender fingers, with a dark grey-silver militaristic uniform jacket, protective armor vest, shoulder pads and gaiter. And black Emeril Lagasse shoes.
You didn't think it would be that easy, did you?
Alex said, it was the physical avatar of Skynet itself, to be exact. An alternate timeline's Skynet. Being cold, methodical, very aggressive, narcissistic and megalomaniacal. Alongside with a superiority complex. Viewing what Team Sonic destroyed as just some army full of slaves. It had more emotions than other Skynet iterations or Tailses from other timelines. This thing was not Tails, this was The T-5000.
I've come a very long way to stop them..
It said, grabbing a barely living soldier of Team Sonic, infecting him with machine-phase matter. The same way it did to Sonic. Using a different victim. The T-5000 viewed it's army and creation as expandable, just slaves. Easy to replace. Having no attachment to them, and never caring about their fate. It was able to infect others, time travel, and had full god-like, omnipotent powers and all Skynet and Legion's units' abilities. With machine-phase matter, mimetic pollyalloy, with instant regeneration and being invulnerable. It's true potential was endless and unknown.