Check for the guide in the OP which has my name on it with the link. Scroll down to the Death Scythe section.
IMO Death Scythe is one of the most underrated and overlooked enemies in DMC. By that I mean most people tend to just spam Helm Breaker/Killer Bee without trying to understand the enemy as he is way more complex than he appears. Like for example people don't know that Nightmare Beta ignores his defense unlike other firearms nor do they know that when he is fully loaded with scythes he is actually more vulnerable.
He is one of those rare enemies which "levels up" the longer the fight goes on. It's similar to the Blades, not many people know that the Blades get more aggressive when Dante is at red health (it's the scent of blood ability) nor do they know that it's possible to "one hit kill" them aka a critical hit. It's little touches like these is why DMC1 still is the pinnacle of enemy designs in an action game.
This thread feels like I have gone back in time to the more awesome years of DMC. Thank you GAF and DMC HD for allowing me to relive these years.