Weapon Coating
You've adopted using weaponry coated in Sea Prism Stone. As such, you're an expert at dealing with Devil Fruit users. At 3rd level. You deal an extra damage die to enemies that are suffering from Suppressed or Disrupted when you hit them with a weapon attack. You gain the following Resolve Ability.
Devil's Dust
You strike out using your Sea Prism weapon. After you successfully hit with a weapon attack you may spend two Resolve to attempt to inflict the Suppressed status effect. The target must make a CON saving throw (DC = Brawl DC) or become Suppressed for 1d4 rounds. Additionally, When you would use it you may spend one extra Resolve to let your target make a Con Save (DC = Brawl DC), on fail they suffer 1 rank of Weakened. (The extra Resolve doesn’t count towards the Resolve limit of that ability)
Cuff Em
At level 6 you're used to locking down the worst of Devil Fruit users and opponents, as a bonus action you may target a Suppressed creature in melee range and attempt to restrain them. The target must Succeed on a STR Save or gain the Restrained condition as well.
100% Purity
You've upgraded the quality of Sea Prism Stone on your weaponry, at level 13 if you land three weapon attacks in a turn on a creature they must succeed on a CON Saving Throw or become Suppressed until the start of your next turn. Additionally the quality of your Sea Prism stone is so fine that it can impact Haki as well. When you would inflict the Suppressed condition you may choose to inflict the Disrupted condition instead.
Lockdown
At 20th level you've become a master at subduing the worst of an enemy's abilities. Once per long rest you may spend five Resolve and your reaction to place the Suppressed, Disrupted, Restrained, and one rank of Lethargic conditions on a target when they would gain any one of these conditions. The duration for Suppressed, Disrupted, and Restrained is 1d4 turns.