Gear 5 is Luffy's most powerful form - here's where its inspiration came from.
Eiichiro Oda Cleverly Shows the Biggest Difference Between Two Forms of Gear 5 Luffy During His Fight Against Kizaru in Egghead Arc - IMDb
How close is One Piece's Luffy to Gear 6?
The Meaning Behind Luffy's Devil Fruit and Explaining the Gear System : r/ OnePiece
What Does Gear 5 Mean For One Piece Final Saga?
What is you exact thought on Gear 5 and why? : r/OnePiece
Eiichiro Oda Reveals the Strongest Form of Luffy Yet That Can Even Beat Shanks But He Still Has One Major Weakness
One Piece Takes a Playful Pivot: Luffy's Gear 5 Revealed! - Saturday AM
The 'One Piece' manga is into its final saga: here's what you need to know
One Piece: Oda reveals the surprising inspiration behind Luffy's Gear 5 - Dexerto