Luffy has mastered his devil fruit through awakening with seemingly no major power up related to it coming any time soon. Outside of the obvious making g4 and 5 less taxing. It’s a stretch no pun intended but maybe he learns logia awakening somehow
He also gained high level haki technique like future observation , penetration armament, and conquerors coating/infusion. I also think flame armament is lowkey a high level technique
When it comes to what he can improve in each category
- Observation haki just needs basic improvements like
- Increasing the amount of time he capable of using it. So he can passively always have it on
- Improve his range/radar
- Armament haki pretty much same as above but instead of range/radar improve its resistancy/toughness
- Conquerors haki idk. There might be other abilities and levels to it we don’t know of
What if his next step is getting a weapon or 2 like nika? Specifically a sword and spear
- Off the bat no it wouldn’t effect zoro or mihawk because luffy wouldn’t be a swordsman. More like big mom, king, or queen just people that can use swords along with a bunch of other things
- As to what weapons specifically I think him getting Roger and whitebeards would be the coolest options
- Also all the emperors have weapons excluding luffy with even Blackbeard having one. Him having his claw weapon that he scarred shanks with and has been seen with even as a child
Same applies to him having powers related to him being a d or monkey imo