Cole Umikumori and MarineMan.EXE

Name: Cole Umikumori
Age: 15
Gender: Male
Appearance: Cole is a dark haired, blue eyed teen. He usually combs his hair downwards, not because he's emo, like most people say, but because it fits his shadowy personality. He usually wears a black shirt and jeans, complete with a dark blue jacket. He keeps his PET in his pocket, often checking to see if it's still there. He also carries around a few pencils, for no reason. People often question this, because nobody has seen Cole write a single thing down outside of school, but he just says "Just in case." when someone asks.
Personality: Cole is kind of a quiet teen, not stopping by to say hello. He often checks around him to see if anyone's watching before doing something. In a netbattle, he's driven to fight to win, often for rewards, so it isn't entirely pointless like he says. The only time he works with others is if his Navi his having a hard time in a Netbattle, if he's on a mission, or if he's forced to.
PET Modifications: Cole's PET is a dark violet and dark blue PET, to match his navi MarineMan. He has a shooter on his PET, letting him shoot the plug out at the jack-in port, instead of having to walk over to it and put it in. It has a red laser pointer, to help him aim at where he's shooting the plug, since he often tends to miss.

Name: MarineMan.EXE
Gender: Male
Element: Aqua
Subtype: Shadow
Appearance: He wears something of a cross between a ninja cloak, and a navy suit. He has a mask, covering a lot of his face, except his eyes. He also carries a gun, bringing out the fact he's a Marine, although he is more of a Navy Seal. His symbol is two guns crossed.
Personality: Almost like Cole, he's a quiet Navi when going around on the Net. Although, when in a netbattle, he becomes fierce. He will always try to win a battle, no matter what. He sort of dislikes working with others, unless if forced or told to. When he does, though, he acts like a drill sergeant, unless if the Navi is superior to him. He also keeps his identity a secret to all, cloaking himself in shadows when almost seen. He's considered the Navy Seal of the Net.
Custom Weapon: For his custom weapon, he takes out his gun, and shoots. For a charged shot, he just fires a huge bullet.
Signature Attack (60/60):

Water Grenade:
MarineMan pulls out a grenade from one of his pouches, and throws it at the enemy, causing a blast and a splash of water on the field.
Damage: 20
Attack Attribute: Throw
Element: Aqua
Effects: Blast2, Small Area Sea Terrain
Cost: Throw Attribute (0) + Same-Type Element Attribute (0) + Damage (20) + Small Area Terrain Effect (10) x Blast2 (2) = 60

And also, Set Ice please.
Hm, well, as it is, it's okay. However, by the way you described it, you made it sound like MarineMan is just wearing a navy blue suit or something. Kind of short, could use expansion.

Some ideas:

Describe the Navy suit by itself, write about its components. Shirt, pants, boots, gloves, what have you. Look at a picture and write a paragraph on it if you want. Same goes for the ninja cloak. We don't even know what color it is. How long and thick is it? How much does it cover? How does it attach to his body, or does it attach anywhere at all, even? Is there any general design on it or is it blank? Does it flap around much? Describe the gun. Is it a revolver? A rifle? A light machine gun? A stun gun? Size? Caliber? Heavy or light? Any special attachments? Describe where his symbol is located, since it's kind of pointless to have it when he doesn't have it on his body to begin with. What are the color of the guns, and the background behind it?

... Also, I forgot to tell you to describe the guy himself. Height/weight? Color of hair/skin/eyes? Body shape? Fitness level? Hair style? Does he have any awesome five o' clock shadow? Anything weird, like scars? Deformed in any way?

It's fine by itself. Just throwing out some pointers that might get you, as well as other people, a better idea of how he looks like, by adding more detail.

PS: Some notes on the operator, he might not be very fun to RP if you don't give him a quirk or something. You can do okay with a generic one, but it's much more fun when you get to explore with something weird. Those pencils seem like a good source. Maybe he likes to draw random things in unexpected places?
I'd like to add, on a more mechanical note, that terrain changing does NOT stack with blast. So your sig's cost works out like this:

- 20 damage = 20 points
- Blast 2 = x2 points
- Small Area Terrain Change = 10 points
Total: 50 points

Thus, you have 10 leftover points, which you could use to add 5 damage to the attack, change the terrain change to Medium size, add a single instance of Knockback...or maybe even something else I can't think of. The decision is yours. : D