It took a little longer than an hour to go back to the Dungeon, most likely due to the added weight.
But all in all, Erza fulfilled the order she was given and arrived in front of the Great Tokyo Dungeon before the knocked out boy woke up.
Going inside the Dungeon, the first thing Natsu did was check whether the boy was alive or dead. And only sighed in relief after he was sure that he was still alive.
After all, if the boy ended up dying outside the Dungeon, Natsu's whole plan would've been destroyed instantly.
As Natsu sighed in relief, Rias appeared beside them out of nowhere with a happy smile.
"Welcome back, darling. I hope your venture outside was successful."
Nodding his head, Natsu said, "It was. All thanks to Erza."
Since Natsu complimented her, Erza blushed happily and was about to behave humbly when Natsu continued talking.
"But tell me, how did you appear beside me so suddenly?"
"Its because I can freely travel anywhere inside this Dungeon, Darling. I can even take others with me."
"I see. In that case, take all of us to the core room."
"Okay."
Following Natsu's order, Rias only looked at all of them and Natsu felt the same sensation as the one before when Natsu was first teleported inside this Dungeon.
Just, on a smaller scale.
With only a slightly dizzy head, Natsu managed to walk without stumbling when he decided that he should purchase at least the basic furniture needed.
Since right now there wasn't even a chair for him to sit in. But, that was after he took care of him.
Turning towards the boy who hadn't woken up yet, Natsu told to Erza, "Kill him."
Not hesitating in the slightest, Erza pulled out a sword from her spatial dimension and began bringing it down to kill the boy in a single go.
Unfortunately just as the sword's edge was close to cutting the boy's head off of his neck, his eyes shot open as he rolled away.
"You... You crazy fools! What do you think you're doing!?!! I possess a Legendary Class! A fucking Legendary Class! How dare you kidnap me and try to kill me?!! I'm going to slaug... "
It was now that Natsu noticed, that the words being spoken by the boy were in Japanese. However, when those words entered his head, he could understand their meaning perfectly.
Most likely due to the DH System.
Turning around Erza looked towards Natsu to see if he wanted her to wait, when he said, "Shut him up by killing him."
Raising her sword once more, Erza began stepping closer to the boy whose eyes became wide showing fear in them for the first time.
By now he had realized that the beautiful woman who felt very familiar was really going to kill him.
"Wait.... I can... "
Unfazed, Erza didn't even stop to listen what the boy was going to stay when she appeared in front of the boy who was grovelling in a flash, and cut his head away before he could even move.
As soon as the boy died a string of notification appeared in front of Natsu, whom upon reading them all smiled in satisfaction.
[Lvl 1 intruder has been killed. Obtained 500 DP.]
[The killed intruder possesses a Legendary Class. Obtained DP X 100.]
[Special reward for killing the Legendary Class intruder. Obtained Appearance Change Card.]
Being the Dungeon Core, Rias naturally obtained the same notifications.
Due to this, she said, "The special reward would've been a better one if he was of a higher level, but the Appearance Change Card is also a pretty good reward since you can't buy it from the Dungeon Store. And it only appears in the combined auctions."
Nodding his head Natsu was about to ask more questions when he saw the boy's body disappearing and turning into dust which was being absorbed by the floor.
Though it was happening very slowly, Natsu couldn't risk the boy's body disappearing before he completed the final step of his plan.
"Rias, buy it quickly."
"Yes, darling."
Not wasting a second Rias immediately bought the item which Natsu wanted.
The next second a golden flash appeared in front of Natsu, followed by which a card appeared out of it.
Stretching his hand Natsu grabbed the card and moved closer to the dead boy, and pressed it against his body in such a way that his blood touched the card.
Once this happened, Natsu received the notification which he was waiting for.
[Using Class Transference Card.]
[Found Legendary Class - Elemental Shooter.]
[Do you wish to obtain it?]
[Warning. You already possess one class. If you obtain a second class, you'll no longer be able to pick another class, or change your existing classes to another one.]
Not hesitating in the slightest, Natsu chose to go through with the process.
Because even though he didn't know how powerful the Elemental Shooter Class was, Rias had told him exactly how powerful each and every Legendary Class.
The next moment Natsu could feel his body turning a little warm, as more notifications appeared in front of him.
[Obtained Legendary Class - Elemental Shooter.]
[You've reached the maximum number of classes one could possess.]
Along with the notification, Natsu saw the boy's body completely disappearing due to which he felt a little relieved from not having wasted any time.
...
When Natsu asked Rias for a method which would let him obtain a class which belonged to someone else, Rias showed him the Class Transference Card.
[Class Transference Card - 45,000 DP]
[Transfer a class which belongs to someone else into you]
[Warning. To transfer someone's class into you, no more than 3 minutes should pass since they have died.]
While this item did bring hope to Natsu about the prospects of obtaining a combat class, alongside his Dungeon Master Class.
Seeing how much it cost almost dissuaded Natsu, when Rias informed him about how many DP he would obtain for every Lvl 1 individual killed inside his dungeon.
And, by how many times the DP would increase if he had a Legendary Class.
This was why Natsu wanted Erza to be careful and not let the boy die before they reached the Dungeon.
Luckily, the boy did possess a Legendary Class, due to which the effort Natsu and Erza put into his plan didn't turn into a complete waste.