Without spoiling too much:
1. Get Backers have 2 MCs, a battle genius and the Jesus of the series (kinda like Zoro and Luffy, right?)
2. The battle genius has more potent skills and AP, but the Jesus usually ends up fighting the strongest opponent in every arc (not always, but around 70% of the time).
3. In their journey, they met a nigh-invincible transporter who fought with blade and scalpels made from his blood. He is a super-calm loner who seeks strong fighters to test his own limit. He is both a foe and an ally at different points of the story and fought both MCs. He completely embarrassed the Jesus who was showing his full power, but got impressed by the battle genius outsmarting (but not defeating) him during a mission (kinda like Mihawk lolnoping Luffy in MF, but then got impressed by Zoro's resolve). He agreed to let them escape, in exchange for the battle genius promising to fight him at one point.
4. Long story short, the final arc involves every major character against a shadowy faction ruling on top of a building which leads to to what amounts as a paradise in the series (see another similarity?). The final arc ends with the Jesus defeating the virtually indestructible shadowy ruler and gaining a way to ascend to Paradise as a chosen one. The final fight of the story, however? The Battle Genius vs The Transporter, mutually agreeing to fight after the final boss is taken down for good. It is THE greatest fight of the series and even now is in my personal best list of one-on-one fight in any Manga/Anime.
What I'm saying is Luffy following the path of GB's Jesus and Zoro vs Mihawk mimicking the Battle Genius vs the Transporter are not impossible. :cheers: