Response 2

1. Counter misconceptions and improper analyses
-Demon false-equivalency
--Senji being demonic is a wholesale wrong assumption.
--Death wouldn't be affected by this anyway due to surviving a hit from the Rod of Arafel, which cleansed an entire city of corruption while he was standing in it.
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-Jackie's piercing durability/"featless tentacles" fallacy.
-Death
2. Destroy "Magnet Power" argument
-Death's Scythe can be teleported back to him.
-Jackie's complete molecular control over his Darkness constructs will allow him to turn anything that's taken from him into explosives.
-Opponent has argued Neptuneman as being tantamount to a passive magnetic vortex in this fight. "Passively pulling metal towards him" gimps his teammate, whose sword has a metal pommel and whose armor is also made of metal. What he's arguing also means his Magnet Power is acting upon all of the metal in front of him in the shipyard, which is almost certainly going to overtax him immediately.
--"Alternatively, my opponent could simply be arguing his character's powers incorrectly, in which case Neptuneman is NOT a passive magnetic force and is going to have to focus his powers before Jackie summons his opening attacks if he wants to nullify anything before the attacks start flying." (And that isn't happening)
-"Standing near him for too long." For HOW long?
3. Set up counterattack
-Jackie: Now has knowledge that one of the opponents is a magnetism user. Can adapt to fight using non-metal attacks, or exploit this via molecular control again.
-Senji: If his rings ARE taken, he'll quickly gain a set of replacement rings or, failing that, can have Jackie open his arms up with his tendrils instead.
-Death: Not even bothered.

As soon as their offense is established after the ultimate failure of Neptuneman's Magnet Power, Neptuneman becomes the primary target, after which Senji most likely just eviscerates him.