Luffy uses Gear 5 in a significant battle towards the later part of the manga. But the exact chapter or arc can vary depending on how you're reading it.
I think it's in a relatively recent chapter, but the exact one might vary depending on where you're reading the manga. You might need to check the latest updates.
Well, in the fanfiction, Gear 4 Luffy might have had some new and unexpected interactions. Maybe he could have teamed up with some other pirates in a different way. Since he was in such a powerful form, he could have inspired more of the pirates to fight back more bravely against the Marines. And his presence in Gear 4 could have also affected the admirals' strategies, making them more cautious or forcing them to use their more powerful techniques earlier.
It would likely make the storyline more exciting. Gear 4 Luffy is extremely powerful, so his presence in Marineford would change the power dynamics. He could defeat more enemies quickly.
Plants vs Zombies 2 Endless Mode required the completion of some special quests to activate. Here are some key steps:
1. In Endless Mode, players need to plant a large number of plants and constantly collect sunlight to grow the plants.
Players need to build a defense tower to protect their homes from zombie attacks.
Players also needed to create some special plants such as Nut Wall and Ice Shooter to resist the attack of zombies.
There are many other levels and missions in Endless Mode. Each level has different difficulty and rewards.
To activate Plants vs Zombies 2 Endless Mode, players needed to collect enough sunlight to build enough defensive towers and special plants, and constantly challenge levels and complete missions.