Complex sentence: As Barry accepts Wally's transition into Kid Flash and trains him, Barry struggles with the temptation to using his powers for personal gain which worsen upon learning the identity of Savitar as a clone of a possible future version of himself.
Split into simpler sentences: As Barry accepts Wally's transition into Kid Flash and trains him, Barry struggles with the temptation to use his powers for personal gain. His struggles worsen upon learning the identity of Savitar, a clone of a possible future version of himself.