Magic was never Scar's strong suit.
So when Skizz brought home a suspicious glowing jar of lilac powder and said he got it from Scar, obviously Impulse was immediately suspicious.
Impulse had been in his factory, making more spooky-themed candies for the upcoming Hermit Halloween Party when Skizz came in with the stuff. After a brief surprise where Skizz picked Impulse up instead of just saying hi like a normal person, Impulse saw the jar.
After a brief tussle over it because Impulse didn't feel like it was safe, the jar went flying and shattered on the concrete ground.
The dust covered both of them, and they passed out.
When they woke up, they both had cat ears on their heads and tails poking through their pants, matching their hair.
And that's how they got to right now, where Skizz had one of Impulse's new ears in his hand, and was scratching behind it gently.
All of Impulse's voluntary movement froze, but he unconsciously leaned into the hand, and he felt a rumbling in his chest and realized with a start that he was purring.