The biggest flex entrance I've seen recently belongs to Qin Shi Huang from ROR.
ROR is a battle seinen in which the humans battle the Gods in a tournament, 1 vs 1 rounds, in order to secure the survival of mankind. 13 humans from across history have been chosen to participate.
Qin's entrance is straight up boss. The panels speak for themselves.
First off, he's fighting Hades, a supreme God in the hierarchy. Look at how hyped Hades is. There's only one man that can beat him according to Bu chan. Goll, who has witnessed Gods like Zeus(The Godfather of the Cosmos), Thor(Nordic's strongest God and berserker), Shiva(The strongest God of destruction in Heaven and a Supreme God), Poseidon(The God of Gods), etc fight, thinks it's unfair to have Hades in the roster. But Bu chan tells her that only the King of Genesis can be victorious against Hades.
And then moving on to the entrance. Qin just shows up wreaking the buildings nonchalantly looking for his lounge. Humans and Gods have separate lounges, with Gods' obviously being much better. As he's wreaking the place he notices the VIP Gods lounge. Obviously an Emperor, vainglorious and cocky, he naturally assumes that the VIP room must definitely be his lmao.
The seat in the picture, the empty one is Hades'. Ares used to sit there before Hades showed up, but since Hades showed up Ares doesn't dare to sit there. Ares is the big muscular one. Instead, even though Hades left to battle, Ares sits on the chair that's about to break thanks to his physique. Now, my boy Qin Shi, enters the Gods' room nonchalantly, no one ever did that before, casually ignores two Gods there, Ares and Hermes, and goes straight down and sits on Hades' seat. The utter shock on Ares' face as Qin sits on Hades' seat is amazing lmao.
Ares and Hermes, confused and wondering, while Qin doesn't give a damn is glorious as well. Ares tries to get Qin to move, wants to grab him for his arm and take him away, but Qin, whilst sitting down, straight up negs Ares in one move, with the flick of his wrist. That even causes Hermes, to move away, shocked. Then my dude Qin proceeds to tell two Gods to humble themselves because they are in the presence of an Emperor. Straight up boss energy through and through.
For number 2 I gotta mention the GOAT Escanor.
The panels that show him off in his intro
I assume most people are familiar with NNT. Escanor appears in the latter half of the manga because he is too fucking strong lmao. Escanor breaks the game, he's the embodiment of unfairness.
What happens here tho is the following. Two Commandments appear at Escanor's bar. Commandments are the highest ranking demons of the Underworld, with only 3 demons, Chandler, Cusack and the Demon King himself, being ranked above them. Their combat classes go from 28 000 to above 100 000. Before the Commandments showed up the highest combat class we saw was like 5000 iirc. Shows you how crazy hyped they are. They destroyed everything wherever they showed up. For the large part of the manga only Escanor could wipe the floor with them.
The deal with Escanor tho is that his power is during the day. As long as the Sun is up, Escanor keeps getting stronger. During the night he is in his normal human form, weak as fuck lmao, his combat class is 15 in that form lol. But as soon as the Sun goes up, you better run away. His power increases the more the sun is up. And when it hits noon, Escanor is literally the embodiment of invincible power.
The two demons visit Escanor's bar at night. Escanor hides Ban and Jericho from them, and the demons wanna drink and play games. Galland challenges Escanor to a game. They will each hit each other and the first one to die or run away loses. Escanor, in his night form, the weak one, says OK. Galland hits him once and knocks him out completely.
The demons continue to drink the night away until morning. Galland notices a huge axe, that he can barely lift. He wonders what kind of axe is it, and how it can be wielded at all. He thinks it's a two handed axe. Escanor, due to morning and the Sun, appears in his buff form now. This is the early morning, so the weakest Escanor is, bar the night of course. Escanor then tells him that he stands at the peak of all races, not lying btw, and that he is the sin of pride.
Galland starts laughing at him, Escanor joins in in the laugh and then casually, while holding back, swings his axe and cuts Galland in half. Melascula shits herself at the sight of all of this.
Galland stiches himself and being angry uses his critical over that increases him combat class from 28 000 to 40 000. In that powered up form he swings at Escanor, hits him in the arms, the shockwaves of the hit travel far and wide and destroy mountains, but Escanor gets nothing but a little cut. And now it's Escanor's turn. As you can also see, Escanor just keeps getting stronger and stronger. He puts the fear of death into Galland so badly that Galland turns around and starts to run away from him. Doing so, Galland broke his own commandment and turned to stone.
A
Commandment is a "cursed" Magical Power created by the Demon King over 3,000 years ago, and bestowed upon ten different elite warriors of the Demons. There are ten in total and each has a unique curse of absolute power bestowed upon anyone who breaks its rule, even upon the holder himself/herself.
Galland was bestowed with the Commandment of the Truth.
The Demon King bestowed Galland with the Commandment of
Truth. This Commandment determines that any who tell a lie in Galland's presence will be turned to stone. Only those who are aware they are lying will be affected.
But it doesn't end there.
Melascula who attacks Escanor's soul directly, and eats it, burns up from the heat of his soul lmao. Melascula's combat class is 34 000.
She entraps Escanor in the Glooming Cacoon. Melascula envelops her opponent in darkness, trapping them within a pitch black sphere. The cocoon is extremely resistant. According to Melascula, even a member of the Ten Commandments could not break it. Although she said that the only time it was broken was when Zeldris used the Demon King's power. It requires the power of the Supreme Demon King in order to be broken and Escanor's soul does it casually lmao.
So there you have it. Two top ranking demons straight up negged by Escanor's power. In the morning nonetheless, when he is at his weakest, bar the night of course.
Two straight up BOSS entrances. Can't get better than that.