Luffy experimented with his Gear 4 mode so much that he was eventually ... When assuming this form, Luffy always has a deadly serious look on his face, adding to the intimidation factor.
Gear 4 has multiple forms as well ... and an ability that essentially makes Luffy fight with immense freedom, with a smile on his face. Most importantly, it buffs up his body even more, and ...
The Gum-Gum Shotgun Was A Unique Variation On A Classic Attack ...