This is a qualitative change.

Because, this allows an action that originally required to consume mana to now no longer need to consume any mana.

Imagine a scenario where for various reasons you have overdrawn your mana to the upper limit, which is -10,000 moles. At this time, if you need to consume additional Thunder Feather, even if you only need 1 Mol, it will cause the "Thunder Feather" contract to be no longer usable until you find a mana supplement and re-release the overdraft limit.

However, the [0] cost is different, which means that you can use it without any scruples, regardless of the limitations of mana.

At the same time, Summer Night also noticed that the time for the "Thunder Feather" to reunite was [10-2N] seconds, where N was the contract rank.

Then, if you sign up for the rank 5 "Thunder Feather", the reintegration time will be shortened to 0, which means that it will become a "no CD" skill, and there is no need to consume any effort to expand the "Thunder Feather", then you can keep spreading the "Thunder Feather" into wings, and at the same time immediately bloom the wings into lightning that attacks the enemy......

She couldn't help but have this image in her mind: she was like a big firework that never stopped, banging, banging, banging......

I really want to test the actual effect of "Thunder Feather" now, remember the last time Luca said that there was an abandoned urban area in the lower city, which was used by many witches as a testing ground for new contracts?

Just as Summer Night was thinking about whether to go out again, the crystal ball resting on the bedside suddenly sounded a "ding dong" prompt, she walked over, picked up the crystal ball and looked at it, and found that it was Yaha who sent her a message.

As the whaling ship nears completion, Yaha asks if she'd like to come and have a look.

So fast?!

Summer Night remembers that the time limit she put forward was one week, and now it has only been three and a half days since the full dozen, and it has been basically completed?

She quickly replied to Yaha: Go now.

"Lilian, I have something to go out temporarily, and I won't be at home for lunch at noon."

Summer Night walked out of the bedroom, already dressed in the clothes she wore for the morning, she said hello to Lillian and walked to the door.

"Huh...... Well, it feels like Sister Summer Night is busy again. ”

Lillian leaned out of the kitchen, still wearing an apron, clearly halfway through cooking.

"I'll be back for dinner in the evening." Summer Night added a little apologetically, and hurried out of the house.

Downtown.

The No. 3 dock of the "Far Ship Charter" is located next to the factory building that Yaha forcibly occupied last time.

When the summer night arrived, Yaha and Chrissy had been waiting outside the dockyard for a long time.

"Miss Summer Night...... Uh, sir. Yaha didn't seem to have figured out what to call her.

Chrissy greeted skillfully, "Lord Summer Night, you're here." At the same time, he bowed slightly and bowed.

"I've been waiting." Xia Ye nodded in response, "It's okay to call me 'Summer Night' in the future, you don't need 'Adult'...... Ah, you finally cut your bangs off. ”

"After all, you ordered it last time." Chrissy said with a wry smile.

It looks much better, but this hairstyle is still bad enough, at least it lowers the appearance score by 0.5 points. Summer Night commented in her heart, but did not continue the topic, she was most concerned about the whaling ship now.

"You said the ship was almost remodeled?" She asked Jaha.

It was Chrissy who replied: "The current progress is 80%, and it will be completed in one day at most, please come over today, mainly to see if there are any other needs, so we can add them before completion." ”

"Then let's go check it out."

"Okay." Chrissy nodded, and led her and Yaha into the dockyard.

……

It turns out that this is the dockyard of this world.

Summer Night looked around and thought silently.

It's very similar to the previous world, although she hadn't seen the dock with her own eyes before the crossing, but through the Internet and TV, she has a rough idea.

If there is any difference, one is that there are no hanging towers in the dock here, and large equipment or materials are basically transported by witch contracts. More specifically, it is a witch contract that can summon a huge skull arm, and a white bone arm with a length of more than thirty meters extends from the summoning array, easily grabbing various materials, and carefully placing them in the designated position under the command of the summoner.

The other difference is that it is not close to the sea at all, which is understandable, after all, the so-called ships in this world are all in the air. When completed, the top of the dock opens to both sides, allowing the ship to fly out directly from above.

Now the three of them are riding on a specially equipped broomstick in the dock, flying slowly around the huge whaling ship.

Compared to the transport ship I had seen in the lower part of the city, the whaling ship in front of me looked very different.

The shape of the ship is about 80 meters, but at its widest point it is only 10 meters, with an aspect ratio of about 8, which is obviously designed for high speed.

The bow of the ship carries a sharp angle of attack, which, according to Jaha, is also a powerful weapon, but only if the captain who wields it has the courage to take the whole ship towards the whale.

In the middle of the ship's side, there is a short winglet on the left and right, which is the horizontal wing, which can control the whaling ship to fly up or down. At the stern of the ship, two huge cylinders are suspended, and the first sight of them on a summer night reminds me of the engines of jet aircraft.

"What's that?" She asked, pointing to the cylinder.

This time it was Yaha who answered: "YT2500 type ether ram thruster. ”

"Aether...... Stamping? "Summer Night heard a completely unfamiliar word.

"Ah, that's how it works......" Jaha gushed about whaling, and she explained in detail how the Aether Ramjet works, and although she said it a little verbosely, Summer Night understood.

After listening to it, her first thought was: It seems that the witches of this world don't only use witch contracts.

For example, the thruster in front of me is a rather industrial thing.

The way it works is based on a simple principle: ether can be "burned".

Aether is a very stable substance, but under the conditions of high temperature, high pressure and specific magic fields, the structure of the aether will also be destroyed, this phenomenon is called "aether deflagration", in the process of deflagration, the aether will release a huge amount of energy, after which the structure of the damaged aether will repair itself and return to normal.

The Aether Ramjet is fueled by whale oil, and when it works, it first sucks in the aether through a mana-driven fan, heats and pressurizes the aether through a contract engraved inside, and builds a specific magic field to trigger the aether deflagration.

The energy released by the deflagration is ejected backwards down the nozzle, creating a thrust that accelerates the whaling vessel. When the whaling ship accelerates to a certain speed, the aether will form an aether wind, which will blow itself into the cavity of the propeller from the front.

At this point, the fan no longer needs to turn, it will stop and lock the blades to save valuable whale oil. The aether wind compresses itself in a specially designed cavity to reach extremely high temperatures and pressures, and when it is induced by a magic field, it deflags, blows out through the nozzle, and new aetheric winds blow in from the front, repeating the cycle and generating continuous thrust.

The cleverness of the Aether Ramjet is that the vast majority of the thrust it generates comes from the energy generated by the Aether Deflagration, and only a very small part comes from the magic generated by burning whale oil. And in the Aether Sea, the most important thing is Aether.

It can be said that it was precisely because of the invention of the Aether ramjet that the witches of Debussota had ships that could sail for a long time, at high speed, and over long distances in the Aetheric Sea, and it was precisely because of such ships that the whaling industry arose.

"So, which genius witch invented this thruster?"

After listening to Yaha's explanation, Summer Night immediately asked.