As the Valkyries were Jetting away from the Honkai Corrupted Sharks. Kiana Looked beheind them and saw that the sharks were behind them.

Kiana: Are All the Fish here corrupted by the Honkai Energy?

Himeko: At this Rate, They're going to catch up with us!

Mina Then Turned behind and started Shooting at the Sharks, killing a few of them, before running out of ammo, and she then loaded her Last mag.

Mina: They Sure are persistent!

Himeko: Looked around her to see anything that might help to remove the threat of the Honkai Energy corrupted Sharks, she then Looked to her Right and saw a Sunken I-400 Submarine.

Himeko: Wait! Look over there!

Himeko the turned to the Submarine.

Himeko: Follow  me!

Kiana: Hold On, Himeko!

Fu Hua: Where are you going?

Himeko: There's a wrecked Submarine over there. If we can lure the monsters in and smash the boulder underneath the hull, We'll b able to trap those bastards inside!

Hime explained her plan as they were being chased by the sharks.

Kiana: How are we supposed to break such Large Rock? We Don't have any explosives!

Himeko: I'm leaving this to you!

Fu Hua: Understood, But I'm going to need three minutes to get ready.

Kiana: Aw, fighting off a bunch of sharks in three for three minutes, should be easy-peasy!

Mian: I'll provide the class monitor with Covering fire.

Himeko: Alright!

And with that the group split into two Mina Providing support to Fu Hua who were Hiding behind the Submarine's broken Hull, and Kiana and Himeko were left inside the Submarines Hull serving as bait for the Honkai Energy Corrupted Sharks.
Once everyone was into position Kiana pulled out her Water Spirit Type-1 pistols.

Kiana: Come at Me! Stupid Fishes!

Kiana Taunted the Sharks as Himeko Grabbed her By water jet propulsion pack, and were propelled iside the The submarine, and once Himeko and Kiana hit a dead end the were ready to make a stand.

Kiana: They've all followed us in!

Himeko: And we have hit a dead end.

Himeko Said as she Pulled out her Broadsword

Outside the Sub Mina and Fu Hua and Mina, were waiting for the Time to break the Rock.

Mina: Alright now we wait.

Fu Hua: Focus... Focus... 

With Himeko and Kiana they were making their Stand, Kiana was shooting at the Sharks, while Himeko was Hacking and slashing at the coming horde of Sharks, one of the Sharks got to close to Himeko and attacked her though Himeko was fast enough and she Slashed it in two releasing it's corrupted blood flowing into the water. Again another shark came at Himeko and again she manged to Killed when she swung the blade at it, though one shark got too close and almost killed Himeko, Though luckily for her Kiana gave the shark a Kick and shot it with her Pistol.

Fu Hua Was standing at the Ready to break the Rock, with Mina serving keeping an eye out for any incoming sharks.

Inside the Submarine Himeko and Kiana were getting tired shown by the sweat that Himeko and Kiana had on their faces. Himeko was using her Broad sword as a shield to keep of the Attacking Sharks. 

Himeko: Fu Hua are you ready? Please Respond!

Fu Hua did not respond as she was concentrating all of her Energy on breaking the Rock, and Mina was looking Nervously, at Fu Hua seeing as the Three minutes were almost up.

Kiana: There's no end to these damned things!   

Kiana said as she was shooting at the Honkai Corrupted Sharks left and Right.

Kiana: Three Minutes should be up by now, Right?

Out side Mina was looking at her Underwater clock.

Mina: Fu Hua when ever you are ready I'd say do it now.

Fu Hua: ...

With Kiana and Himeko they were forced back to back, with the Honkai corrupted Sharks swiming around them. And outside Mina was Looking at Fu Hua with wide Eyes.

Himeko/Kiana/Mina: Fu Hua!

Fu Hua: Right Here!

Yelled Fu Hua as she was about to punch the Rock, with all the force she had. Then her Fist... stopped just shy of the stone's surface?

The scene fades to black.

TBC  

Also What do you think of a Ben 10/Halo Crossover with an OC Forerunner I'm Calling Shield of eternal Endurance