Monkey D. Luffy is one of the Four Emperors of the Sea in the One Piece world, a title he received after defeating the strongest creature alive, Kaido, in the Wano Country arc. After being defeated repeatedly by the former Yonko, Luffy ended up awakening his Devil Fruit, and this awakened form of his is what he calls Gear 5.
Towards the end of the Wano Country arc, Luffy displayed quite a few Gear 5 techniques to the fans. However, he has now added to them during his fight against Lucci on Egghead Island. Fans know a lot more about Gear 5 and its existence, along with what else it has to offer.
6 Gomu Gomu no Dawn Whip
Luffy clashed against Rob Lucci very recently in the Egghead Island arc and immediately went into his Gear 5th form. One of the most intriguing things that fans found out about Gear 5 in this arc was the new naming of techniques. Usually, Luffy attributes certain names to techniques that he only uses upon the activation of his Gears. For instance, the prefix 'jet' was added to his Gear Second attacks, and after the timeskip, this prefix changed to "hawk" when he used it with Haki.
Similarly, Gear 5th has the prefix 'Dawn' that Luffy has only recently started adding to his techniques. Dawn Whip is what he used against Lucci very recently where he spun his body several times, wrapping his leg around himself and then striking Lucci with it right across the face. This technique was so powerful that Luffy could not stop spinning for quite a while afterwards and even dug himself into the ground.
5 Gomu Gomu no Kaminari
Used in the fight against Kaido in the Wano Country arc, Gomu Gomu no Kaminari is a situational technique Luffy only uses when he takes to the skies. Given that Gear 5th has the properties of turning anything, even inanimate objects, into rubber, Luffy was seen grabbing lightning directly from the sky and hurling it at Kaido. Unfortunately, this attack missed and was quite easy for Kyle to dodge, however, it goes without saying that it is very powerful.
Thanks to this, Luffy can somewhat channel the power of the Goro Goro no Mi without even having the Devil Fruit. In the future, fans might see this technique return once Luffy fights in the open skies again against the powerful force that can rival the likes of Kaido.
4 Gomu Gomu no Mogura Pistol
Mogura Pistol is a powerful technique that Luffy recently developed during his fight against Rob Lucci. As the name suggests, this technique draws some inspiration from his fight against Charlotte Katakuri. Mogura Pistol sees Luffy channel a powerful punch in a random direction directly into the ground and then, using the powers of his awakening, turn the ground into rubber and changing its direction to land a powerful blow right into the gut of his opponents.
When he used it on Lucci, the latter felt tremendous amounts of pain and coughed up blood immediately. Mogura Pistol is very similar to one of Katakuri's techniques known as Power Mochi. Upon being struck by it, Lucci immediately took significant amounts of damage, which just goes to show that Gear 5 offers a whole new level of power to Luffy.
3 Gomu Gomu no Dawn Rocket
Gomo gomo no Dawn rocket is yet another powerful technique that Luffy used recently against Rob Lucci. Instead of using his arms to launch himself in the air as he does regularly, Gear 5 sees him use the structures around him to lunch himself in the air and then slam into the gut of his opponents with his fist. This technique was extremely powerful when used against Rob Lucci and was deemed enough to make him lose consciousness.
Thanks to the awakened powers of the latter, Lucci was able to survive this technique as well, however, the vast gulf in the abilities of the two fighters was very apparent. Dawn Rocket remains to be one of Luffy's strongest techniques, even without the usage of Conqueror's and Armament Haki.
2 Gomu Gomu no Gigant
Gigant is a technique that Luffy first used in the Wano Country arc when he fought against Kaido. After awakening Gear 5, Luffy tested its limits to the extreme and did things that one wouldn't have expected him to be capable of. Not only did Luffy do ridiculous things like grabbing lightning and running in the air, leaving fire trucks behind him, but he actually managed to turn into a giant himself.
Using the principle of Gear. Third, Luffy managed to inflate his entire body and turn into a giant that dwarfed even Kaido in his dragon form. He proceeded to use Kaido as a skipping rope, which was quite embarrassing for the Yonko. While this technique wasn't all that effective back then, in the future, Luffy will certainly use it much better.
1 Gomu Gomu no Bajrang Gun
Bajrang Gun is, by far, the strongest technique that Luffy has developed in Gear Fifth so far. This technique sees and makes use of everything that he has got. While using Gear Fifth, Luffy creates a fist big enough to dwarf an entire island and retracts it just like he does in Gear 4th. This fist is then coated with both Conqueror's and Armament Haki to the fullest.
At the same time, Luffy then goes on to locate his enemy with Observation Haki and launches this giant fist towards them. To make things even more dangerous, he uses the power of Ryuo to do damage to his enemies internally without even touching them. When used against Kaido, this technique was strong enough to utterly decimate his strongest Flaming Dragon Form and knock him out completely, breaking one of his horns in the process and defeating him.