Sin Mal/Seaside Overlord

Sin Mal came to the beach with Bronya and Seele.
At first, Sin was actually reluctant, but because Bronya and Seele were both coming, Sin reluctantly agreed.
However, unexpectedly, after coming to the beach, Sin became the most energetic of the three.
-Seele put on sunscreen and hugged her knees under the parasol; Bronya used the secret guide to play the latest game and tried her best to improve her score from "good" to "perfect".
On the contrary, Sin was on the beach "pew pew" using the water gun, "bang bang" playing volleyball to enjoy the fun of the beach, play a lot of fun.
Then, looking at the two people shrunk under the parasol, Sin Mal smashed the volleyball in her hand without hesitation-
"Sin Mal, what are you doing!"
"Hehehe, idiot Seele, and Bronya - you two were so excited just now in the car, why did you go on the beach? Come and play in the sun!"
Faced with Sin Mal who held her head high and declared so, Bronya and Seele could only be speechless.

After staying at the beach for a while, Sin Mal got tired of all kinds of things on the beach and decided to go to the bottom of the sea to play.
Compared with the cautious gestures of the others, Sin only wore goggles and jumped into the sea. At this time, Seele hadn't even had time to sue her.
"Sister Bronya, Sin Mal will not be a problem, right?"
Bronya comforted Seele: "It doesn't matter, Sin Mal should be back later."
However, as time passed by, looking at the smooth and waveless sea, even Bronya lost her confidence:
"Could it be that Sin really has a problem?"
And just as the two became more worried, a trace of ripples appeared on the sea, and then shark fins and whale tails appeared on the sea, as if they were chasing something or being chased by something.
The tourists on the beach were all stunned, including Seele and Bronya, their eyes widened.
A group of killer whales and sharks slowly swim up to the surface, and on the back of the shark in front, the girl is laughing wildly:
"Hmph! How could these things can beat this uncle!"
In the end, due to the influence of Sin Mal, Bronya and Seele finally left the shade of the parasol: diving, surfing... Although they felt dizzy at first, they were quickly assimilated by the warm atmosphere on the beach.