Darth Vader Turns A Lightsaber Crystal Red
From – Darth Vader Vol. 2 #5
Palpatine Explains Why He Tried To Replace Darth Vader
From – Star Wars: Darth Vader #20
Palpatine Reminds Darth Vader Of The Ways Of The Sith
Emperor Palpatine had Cylo IV create enhanced beings that could replace Darth Vader. From – Star Wars: Darth Vader #6