The Sea titan (Attack on Titan）

Executioner From Hell

"Alright squad let's go test our new weapon!" He announced.

"Yes sir!" They answered.

"Wow mother, i must admire your ingenuity, this is beyond my own thinking." He praised the ecstatic section commander.

Hanji managed to come up with a new weapon that had a very nice ring to it's name. 'The executioner from hell'

It worked kind of like a flat guillotine. Using Eren's hardening they created a intricate structure to act like a pillory. The titan would cram it's head inside and a large log extracted from a big tree courtesy of him would be set loose on to it.

Built right outside of Trost's sealed gate it would be perfect for luring titans in as they are attracted to the location.

Now is their first ever test run of it.

Waiting a top one of the extended pillars of the wall he watched as a twelve metre crammed it's head into the gap. Then, the log was set loose and it plummeted upon the titan.

"Oh! A direct hit on the nape!" Hanji announced. "This could be it!"

"We did it! That's a 12 metre, crushed!" Hanji squealed behind them. "Hell, yes! With this, we can kill Titans without a single soldier fighting! We'll hack down the Titans all day and night! Say hello to the executioner from Hell!" Hanji screamed, posing dramatically.

As she said this Eren collapsed, an abnormal amount of blood leaking out of the boy's nose. Reacting quickly he brought out a jar and collected a few samples of his blood before handing him a napkin.

"Are you ok honey?" He whispered to which the boy nodded.

"We did it, Eren!" Hanji turned around before pausing when she saw Eren's condition.

"He overdid his hardening, I'm worried, all we've been doing is hardening experiments it probably took a toll on his body." He explained, to be fair it was also taking a toll on him, so he took the opportunity to make his own life easier as well.

"It's alright, I'm just tired, let's continue making weapons so we could return to shiganshina." Eren gritted his teeth, wiping blood off of his face.

Speaking of weapons.

They have made a few.....

1. Hardening blades: Manipulating his titan hardening, he created a mid weight material that could easily slice through the titan's skin. With his expert control he made sharp small pieces of titan hardening with the exact same size as the normal Anti titan blades. These sheets of titan hardening don't even use up a lot of his energy so he was able to produce a lot.

After a few experiments it is found that under the right user it could even break through lesser titan hardening like the one he uses, though it is still next to useless against the Armoured titan. Currently he made enough sets to be distributed to all scouts. The fact that it can't break makes it an extremely powerful tool. Now the scouts will no longer face the problem of their blades breaking, which saves space in the carts for other weapons and more provisions.

2. Thunder spears: He didn't make it but it is certainly a powerful weapon! The engineering corp really pulled through for this one! It is essentially a hand held missile. Firing it would allow it to embed it in the titan, then when the pull the detonator it would explode, it should be strong enough to take down the Armoured Titan's Armour.

This is the future generation of titan hunting weapons, he was a personal advocate for mass producing these as Anti titan weapons. Plus the fact that it can easily be implemented into a standard ODM gear suit would make it very useful.

3. Anti Titan Mortars: With massive help from the more experienced engineers and his own limited knowledge of Artillery, they came up with a mish mashed and compromised design that still works well enough. A small cannon that could easily be assembled and used in engagements. It could even be used on a cart to create this world's first interpretation of a tank!

After a short field test where it was fired from the wall it was proven that the blast from small cannon balls are enough to kill a titan. Later he made another experiment set up where he made his squad commit to a field test which terrified them but also made them earn his trust, a story for another day. Whatever the case, it is proven to be effective even at ground level. As demonstrated by his squad they could fire between the titan's eyes or at their legs to disorient them before another scout finishes them off.

4. Ironclads: With his help in design they created Steam powered ships to use in the river, although it does present some problems at times for the usual water traffic it is proven to be far far faster than the normal river barges. In addition to being fast water transport if the walls were to be breached again these Iron clads could be armed and would be quite deadly against the titans. With Hanji's research he found that titans usually struggle to break through metal.

This design earned him favors from the naval yard of the island as well. Since there has been almost zero improvement in water travel in an extremely long time. This is part of his plan to modernize the walls. With introducing steam power in the civilian aspect of society the Industrial Revolution is bound to take place.

5. Comet Gun: Creating a new trigger and with his help the Engineering corp developed an early version of the rocket launcher, using a modified version of the thunder spear and a special launch tube it would become a powerful long ranged siege weapon with the range of nearly 300 metres when fired in an arc which is great for the time.

Firing like a missile, the thunder spear would travel forward for a long distance before blowing up upon contact. While in the air the thunder spears glow and leave a trail of smoke hence the name. Useless against normal titans due to the normal firing method of the thunder spear, but would be extremely powerful against human structures.

He has certainly been busy.