As you can see some of the characters have a slightly or completely different design from their canon one, including Mettacrit, Ser Scratchalot, Chara and Undyne (I changed it again because I felt like her robotic arm wasn't "cool" enough in the previous version so now it levitates and she can controls it remotely).
Now i'm finally done with that, but I still have one more idea in mind related to TS!Underswap. You'll find out soon enough, so stay tuned!