Attack Gainer? Seriously? Necromancer and Avenger are also damn random.
For Red Deamon Archefiend, it's ok, as you have several ways to call it out. But for Scar-Red, I don't see much ways to bring it out besides using (bleh) Attack Gainer.
Replace Attack Gainer with Effect Veiler, it's 1000 times better than Attack Gainer which has an awful effect.
Dark Illusion and Negate Attack also very random. Take them out and replace with cards like Limit Reverse or One for One.