This took way too long to make...

"Hey human. Kappa and humans have been sworn friends since ancient times, so let me tell you something."
"Sworn friends? Are you sure you haven't mistaken an old enemy for a friend?"
— Nitori Kawashiro and Reimu Hakurei (Mountain of Faith Stage 3)

The 018-KN (Codename: Nitori) is a twin engine, single seater, high speed, high maneuverability, half tank-half jet transformer fighter. This... can't be called an aircraft, it can't be classified as a jet because half of it is a tank, it can't even be classified as a tank either because its main shape is a jet, so I will just call it a "thing". Anyway, this thing is by far the heaviest fighter I've ever built. This war machine was based on the leader of the kappa in Touhou Project, Kawashiro Nitori. Character's wiki:

General Information
She first appeared as a stage 3 boss in Mountain of Faith and then became a playable partner with Marisa Kirisame in Subterranean Animism. She was later a Day 6 boss in Impossible Spell Card, and a playable character in Hopeless Masquerade and Urban Legend in Limbo. According to ZUN, there were also plans to make her a playable character in Touhou Hisoutensoku, but she was scrapped due to time constraints.

Personality
Nitori is a shy kappa by nature and if she is alone and sees a human, she'll run away, like in Mountain of Faith. She considers herself to be superior to humans and even other youkai and when she's by herself it's easy to see. However, when among her own circle of friends, she is quite cheerful. As a kappa, she is easily persuaded to leave you alone by a cucumber or two. However, she has a greedy side when it comes to running a stand and is quick to come up with plots to maximize profit.

Abilities
Manipulation of water
Her ability to manipulate water is inherent in the fact that she is a kappa, and has nothing to do with the myriad tools she uses. No one knows the true extent of this power, but she has been seen to use it to shoot water, create fountains, perform theatrical tricks and even summoning colossal tidal waves.

Using tools
Akyuu makes a note that kappa, historically, have had an trait called tsuuhai (??), which means their arms are connected inside their body and they can stretch one arm by retracting the other. However, it is said that they are actually just using tools to make it seem as though their arms stretch. In Wild and Horned Hermit chapter one, Reimu receives a "kappa's arm" that ends up being a mechanical arm. In Hopeless Masquerade, Nitori is also seen using several arm-like machines to attack.

Occupation
As she is an engineer she is very interested in products made by the humans of the outside world. She takes such products apart and puts them back together in order to understand them. However, she has trouble creating magical tools of any sort. She is fond of selling her inventions and other things such as Fish as her story mode in Hopeless Masquerade details her attempts at running a stand before getting sucked into the battle. According to Hina Kagiyama, she is also somewhat of a leader figure for the kappa.

Possessions
Nitori possesses many small devices and objects and carries them all in her backpack.

Jet's informations:

Maneuverabilities:
-Roll half a circle in 1/4 sec
-Pitch 180 degrees in ~6 secs
-Jet's top speed is 1700+ KMPH
-Tank top speed is 310+ KMPH

Weapons:
-6x combat missiles (available in jet mode)
-2x ground to air missiles (available in tank mode)
-1x cannon (unlimited)
-4x torpedoes (available in jet mode)

Activation groups in the flight instructions.

VTOL down for flaps, trim for trim.

Normal jet controls, tank controls: Pitch and roll. Have fun!