I honestly have no clue if this is spite in either direction. If it is, then I'll just get it closed.
So! Jack confronts Aku once again, and has him on the verge of defeat. This time, Aku considers Jack too dangerous to keep in his realm, so he opens a portal in reality, sending jack into the Grand Line. He crashes onto the Strawhat crew's ship, trashing Luffy's lunch. Let the battle begin!
__________________ -"My internet is currently so bad I'm time traveling. Don't worry about it."
-"You have the best problems, Scenario. You really do. haermm"
He has jumped hundreds of feet in the air with 10-20 ton boulders, lifted a 700 ton sumo, has survived re-entry into the atmosphere, is fast enough to effortlessly block minigun bullets with one hand, fought the Scotsman for what was I believe three days(by memory, could be wrong) non-stop, killed a group of bounty hunters before a drop of rain hit the ground, regularly displays speed to kill several men without appearing to have drawn his sword, let alone move, and his sword itself is very broken, Luffy already has a weakness to swords(at least compared to his blunt damage resistance), Jack's sword will slice through him clean like butter.
There are few people in OPverse Jack could not beat, it would take a powerful Logia to take him out, and only if they were at a distance, because Jack could very possibly cut them.
Don't forget, there was one time I believe when Jack was in a bar and a bunch of bounty hunters were, and then they all just fell over dead (well they explode since everyone's a robot in that show), nobody even saw him move.
Luffy was trapped between two buildings, and pushed them away from him.
He ripped the front end off of a ship.
Luffy routinely blocks, anticipates, and dodges attacks that are too fast to see, or he shouldn't be able to see.
When he uses his Gear 2nd, his attacks happen so fast, they produce sonic booms.
And before he got the gears, he was fighting Kuro, whose Shakushi is about the same speed as Soru. With Gear 2nd, he overcame that speed, moving faster than Lucci.
Gear 3rd makes his body parts so big and hard, Jack won't have the strength to cut through it, or dodge the hit.
It can cut anything, but if he doesn't have the strength to cut through it, then it's meaningless. Adamantium can cut through anything, but Logan can't, since he's not strong enough to generate enough force to cut through anything.