As many people have already pointed out:
-Between Saturn and Kizaru, Luffy has only expressed a desire to fight Kizaru. Oda specifically had Luffy be out of commission when Saturn came in to be the main threat.
-Luffy has explicitly stated that Kizaru is a "super strong" opponent, and that its his job to protect the crew from Kizaru
-Luffy and Kizaru's first bout ended in a mutual KO, no matter how much coping is done by anyone to say otherwise
-Kizaru was not paying much attention to Luffy the first time around as he was trying to kill Vegapunk, this time around will be a more direct fight than before
-Its been made clear that Sanji and Franky cannot hold off Kizaru, and Zoro is still occupied by Lucci
-Luffy saying "this is getting fun" and laughing after punching Kizaru is similar to when he first went went G5 on Kaido, its clear he is ready to fight Kizaru again now
Maybe I'll be wrong, but I don't think anyone on the island has the power to hold Kizaru off at all. It has to be Luffy still.
However I also know that Saturn HAS to be defeated this arc and that Luffy/Sun God Nika HAS to be the one to do it.
I can see three possibilities here:
1) Luffy defeats Kizaru, then defeats Saturn back to back
2) Luffy fights Saturn and Kizaru 2v1 and beats them both
3) Bonney uses a full potential Nika-ish future to defeat Saturn with the help of the pacafistas.
I like the 3rd option the most because it has the most thematic weight to it. Obviously Bonney gets revenge for her mom, but the Pacafistas defeating Saturn is basically like Kuma defeating him.
Also the CDs are false gods, so the only thing befitting of them is being defeated by a false sun god.
Finally, Saturn/Kronos in mythology is the god of time and was famously defeated by his children, the Zues and the Olympians. Saturn's regeneration might be him reversing time, so Bonney's fruit might be the only thing capable of defeating him. Also, if both Bonney and Kuma were born of Saturn's experiments, then they would be his "children" defeating him like in the myth.
-Between Saturn and Kizaru, Luffy has only expressed a desire to fight Kizaru. Oda specifically had Luffy be out of commission when Saturn came in to be the main threat.
-Luffy has explicitly stated that Kizaru is a "super strong" opponent, and that its his job to protect the crew from Kizaru
-Luffy and Kizaru's first bout ended in a mutual KO, no matter how much coping is done by anyone to say otherwise
-Kizaru was not paying much attention to Luffy the first time around as he was trying to kill Vegapunk, this time around will be a more direct fight than before
-Its been made clear that Sanji and Franky cannot hold off Kizaru, and Zoro is still occupied by Lucci
-Luffy saying "this is getting fun" and laughing after punching Kizaru is similar to when he first went went G5 on Kaido, its clear he is ready to fight Kizaru again now
Maybe I'll be wrong, but I don't think anyone on the island has the power to hold Kizaru off at all. It has to be Luffy still.
However I also know that Saturn HAS to be defeated this arc and that Luffy/Sun God Nika HAS to be the one to do it.
I can see three possibilities here:
1) Luffy defeats Kizaru, then defeats Saturn back to back
2) Luffy fights Saturn and Kizaru 2v1 and beats them both
3) Bonney uses a full potential Nika-ish future to defeat Saturn with the help of the pacafistas.
I like the 3rd option the most because it has the most thematic weight to it. Obviously Bonney gets revenge for her mom, but the Pacafistas defeating Saturn is basically like Kuma defeating him.
Also the CDs are false gods, so the only thing befitting of them is being defeated by a false sun god.
Finally, Saturn/Kronos in mythology is the god of time and was famously defeated by his children, the Zues and the Olympians. Saturn's regeneration might be him reversing time, so Bonney's fruit might be the only thing capable of defeating him. Also, if both Bonney and Kuma were born of Saturn's experiments, then they would be his "children" defeating him like in the myth.