Eh I got a stupid suggestion but it might make sense. I reference Rurouni Kenshin a completely unsimilar story except for the fact that Kenshin post hitokiri never kills. Neither does Luffy. My idea is just like that guy that Kenshin fought in the first story ever. Luffy will injure Lucci's legs/arms so much that he will never be able to use his techinique again.
It's completely different.
Kenshin does not kill ANYMORE. He used to be a vicious killer that slaughtered hundreds of people for the government. When he abandoned that life, he abandoned his murderous ways. When a samurai chooses to seperate himself from a shogun, he becomes what is known as a Ronin and wanders Japan. Some ronins are in service of a shogun, but many (like kenshin), were simply travelers that had no intention of giving up their status as a samurai (Japan, even today, is a very class-oriented society. Being a samurai meant you had several privleges that most people did not, such as being able to carry a katana). Many were mercenaries that killed or solved crimes for money. You should read Samurai Executioner. It's about a ronin that was paid to do executions all over Japan. He was also a mercenary that solved violent crimes by violently killing whoever committed them.
Luffy does not kill because it's pointless. Luffy beats the holy living crap out of people because they are corrupt. Everyone Luffy has fought has had a dream. Even Bellamy, who laughed at other people's dreams, had a dream for the New Age Pirates.
In a sense, Luffy is not killing people because he wants them to dwell on what they did. Krieg, Arlong, Crocodile, etc., remember what almost every character's reaction is just before Luffy beats them? It's something to the effect of:
"He's fighting?! Against me? Against my strength?!"
It's something of an eye-opener.
Anyway, I still stand firm on what I said earlier. Luffy will beat the holy living snot out of Lucci. One of the VA or one of the three Admirals (Sukazuki, probably), will come and kill Lucci for disgracing the World Government, similar to how Doflamingo killed Bellamy for disgracing the New Age pirates.