Never had or seen a bright red brittle, sounds excellent. Is it smooth or spiky? If smooth then it's a serpent star, spiky is brittle star, at least I think that is correct. I'm sure to be corrected if not.
I had some small greyish serpent stars (smooth ones) with bands on their arms once. They had to be removed as they ate anything they could ambush, including other starfish.
I have a dark reddish brown brittle (spiky) star and he is great, had him for 8 years. He mostly hides in the overflow box now since my coral banded shrimp developed a taste for brittle star arms. They catch drifting food in their arms and transfer it to their mouth like a conveyor belt using their tiny tube feet. Amazing creatures.