One Piece: I'm Mihawk's Son

The prototype weapon caused so much destruction that while everyone was shaken, Veyron couldn't help but smile and laugh out loud, flashing away from Crocodile's strike like a thunderbolt. 

"Hahaha, it works!".

"You psychopath... you haven't changed at all" The warlord groaned and recalled his sand, looking at the destruction produced by the weapon that looked no bigger than a sword. 

'If those weapons are produced en-masse... Veyron, you...'

On the other hand, a gust of darkness flashed next to Veyron and grasped his shoulder, a drop of sweat rolled down his forehead. 

"Sweetheart, you didn't test that weapon before giving it to Vivi?".

Robin was already a bit spooky, to begin with despite her beauty, but when she tried to be scary... even Veyron had to step back.

"I did! I swear I did! but I tested it under special conditions, so-"

"So you didn't test it properly?" She frowned further. The tables had turned after the promise... before, Veyron had the upper hand in every argument, but now... it was like his real marriage life had started. 

"I didn't know it was going to be that destructive! Vivi, didn't I teach you how to use that?!" There was only one tactic he could use to get out of this, shift blame. 

"You never said it was a weapon of mass destruction!" The princess cried with actual tears, afraid for her life, that was until Veyron recalled her on an important detail.

"There is a dial to the side to adjust the magnitude, you forgot about that?!"

The truth dawned on her and she looked to the side of the weapon, certainly... the dial was placed to the maximum capacity and the shot had been so strong that all the battery was consumed in one go. 

"... Oops? I think it is out of battery".

"Fool, don't say that out loud!" Robin resisted the urge to sigh and flashed away, temporarily forgiving her lover but with a promise of furthering this discussion of his reckless experiments. 

"Take that weapon away before she uses it again!" Crocodile billowed and both Gem and Galdino got into action after recovering their bearings, sadly though a wave of snow washed them away from the city... there was enough snow in the region now that the sand almost couldn't be seen anymore. 

"Monet, help Vivi and Robin. I want all of them alive".

"Yes, master!".

With all members of Baroque Works out of the city, things could now get a bit explosive. 

CHAAAA!!!

Veyron nearly teleported in front of Crocodile, grasping the latter by the head. 

"Let's stop playing around, Croco... I could be creating things like that weapon in my workshop or having lots of s*x with my wives in the bedroom and instead, I'm wasting time here with you".

!!!

"Bastard, what did you say!?"

"You heard me!".

BOOOOOOOMMMMMMM!!!!

The battle changed directions up to the wilderness of the desert where the snow had yet to reach. Veyron blasted Crocodile into the ground, but the latter didn't let go and instead grabbed him by the neck with a pirouette.

BOOOOOOMMMMMMM!!!!

The Lightning God regained his footing after getting thrashed to the ground, kicking the sand that tried to catch him and levitating as the whole world of sand around him seemed to gain life as Crocodile triggered his awakening. 

Blue lightning manifested in both of his hands before he shot them both in the direction of Crocodile. 

CHAAAAAA!!!

BAAAANGG!!

BAAAANGG!!

Two instant explosions wrecked the soil, melting the sand and turning it into glass. Several clones of Crocodile were produced, all of them with small tornadoes in their hands. 

BOOOOOMMMMMMMM!!

BOOOOOMMMMMMMM!!

BOOOOOMMMMMMMM!!

A brutal exchange took place in which Veyron continued to thrash lightning strikes at Crocodile, melting the world, while the latter threw compressed shockwaves of sand towards Veyron, in the process he cleverly continued to shake the rain clouds that agglomerated in the distance. 

"I told you I'm not the same! Hmph, as long as I'm in this desert, why should I be afraid of you".

He kicked the ground harshly and a wave spread across the world. 

It reached the farthest end and the incoming ventiscas and storms began to wither as the moisture left the air at amazing speeds. Veyron created a sword of lighting and flashed to the ground, flickering across and arriving in front of Crocodile.

RUMBLE!!!

CLAAANGGG!!!

The latter received the strike with his golden hook imbued in Armament Haki, but with Veyron's strike which compressed astonishing Conqueror's will, all he could do was see with stupefied eyes how his feet left the ground and he was shattered like a ragdoll to the distance. 

BOOOOOOMMMMMMM!!!!

"So what if this is a desert... you can't outpower me in any form of haki. You can't outpower me in physical strength. You're not faster than me. You're not more destructive".

He flashed and arrived in front of the groaning warlord, stepping on his chest and planting him back into the ground.

"I didn't just come to help Robin. Be obedient and turn back into my loyal dog... I want to create another workshop in Amazon Lily to be closer to my girls while I'm working. I'll need you again to do the boring for me~"

"I hate you, Veyron! NEVER AGAIN!"

BOOOOMMMMMMM!!

Crocodile's refusal was clear as an explosion of sand and a warcry gave way to a huge agglomeration of sand coming together. Veyron had to retreat as a colossal mountain of sand created a huge shadow in the world.

He lifted his eyebrows a bit in confusion as a titanic form the size of the biggest mountain, stood in front of him. 

And this mountain... had two huge mountains attached to it.

"W-What?"

"I'll never be your dog again! BASTARD, I HAVE MY PRIDE! STOP TREATENING ME LIKE I'M YOUR TOY!".

"Why is it a woman...?"

"..."

The clueless Crocodile looked at his own body, Veyron looked as small as an ant from that perspective, but there was something undeniable about this form. It had two humongous mountains made out of sand, long hair and feminine traits.

"N-NO!"

The form quickly began to shift, transforming into a man that did resemble Crocodile, but by the time everything was done... Veyron's mind was more than muddled and confused. 

"What did I just see..."

"YOU SAW NOTHING!".

A gargantuan fist came along a shockwave of compressed sand, the titanic form moved way faster than anticipated but still way too slow for Veyron's perception. The impact of his fist was destructive enough to shatter a city. 

Veyron was too distracted putting two and two together to even dodge the strike. In the last second, when the fist was about to meet him, he had an 'eureka' and flashed away from the impact zone.

BOOOOOOOMMMMMMMMMMM!!!!

A cataclysm of devastating proportions took place in the spot of the impact with a domain of compressed air being created and leaving a crater. This was truly Crocodile's final form... and it couldn't be underestimated. 

But he had exchanged speed for destructiveness.

Veyron reappeared like a bolt of lightning in the skies, looking down at him. 

"I had my doubts all along you know. At some point, I was even jealous of you. Back during those years, Robin seemed to be closer to you than she was to me. I stalked you both to make sure nothing happened... but you never made a move and that was very suspicious to me as you held her in a good eye-"

"Shut up- w-wait you stalked us!?" Crocodile didn't even know what to be shocked at. The fact her secret was discovered... or the fact that they had been stalked for years by this psychopath. 

"Robin too seemed to have abruptly changed her views on you. So it was this... she discovered you were a woman".

!!!

"The secret that you have that Ivankov knows... is it that you're a woman? Wait a second... come to think of it you do have an Okama in your crew, Bon Clay. Could the two of you have met before-"

The titan stopped in his tracks and gave Veyron the most poisonous gaze.

"How... do you know...? Ivankov... did that bastard tell you?! Or was it Inazuma... whom have you met?!" Crocodile's flustered response only served as a confirmation, that shook Veyron to the core. 

At that moment he felt like he had made a major discovery that he shouldn't have known.

In the manga, during the arc of Impel Down, this was implied... Emporio Ivankov knew a secret of Crocodile. Many theorised it was that Crocodile was a woman based on some other appearances of his character... but he always thought Crocodile was too masculine to have been a woman. 

"Oh my god... the theories were right. Could it be... are you Luffy's mother too?!"

"Who the hell is Luffy?! Shut up and answer my question, when did you meet Ivankov!?"

'Okay... so the theories were half-right. But still, this guy... he's a woman?! Can she be any more boyish?!'