Mercenaries are Level 725 NPCs located in the Second Sea. They spawn near the Colosseum. They have ~8000 HP, 261.2 base damage, and a move which lifts the ground, dealing damage and launching anybody hit. Elemental immunity activates at Level 741.
Level Required: 725
Mercenaries are easy to grind.(only for people without Buddha or a Logia) If you are grinding npc's for a fighting style or sword mastery, you can use these mercenaries as they are the easiest barely breaking ken haki.Use autoclicker, for one of the npc's they're near the wall.Go behind the wall and start autoclicking.Due to your animation, you get pushed back, however One of the mercenaries are near the wall so even if you move, you can still hit them, only that one though.They cannot hit you through the wall, only with one attack that only uses up one dodge that kicks you up, but doesnt knock you back.Another thing, if your sword/fighting style dashes, no problem, Use tiny task and only use 2 or 3 clicks without the dash.If you wanna grind safer, go on top of the tent and use ranged attacks that have Good aoe or at least decent for example venom and use those ranged attacks on then overnight with tiny task.You can do this for fruits such as venom as i did.