3 days later

As the minutes ticked away, the atmosphere around the tower grew tense for William mentally.

He monitored the fog-covered landscape, anticipating the first signs of the approaching threat. The defense bot stood silently, its square head moving left and right for proper surveillance every few seconds.

Suddenly, the timer went down to 0 and William clenched his fists, steeling himself for the challenge that meant either death or survival.

The notebook containing the Mana shot was laid inside the tower safely as he focused on the defense bot and the task at hand.

Suddenly, a silhouette emerged from the thick fog, a Gremlick with the same face as the last one, there was malicious intent in its eyes. 

Without hesitation, William commanded, "Defense bot, target the Gremlick and unleash your arrow." He gave a proper command for a proper action.

William saw the Gremlick being confused while looking at the machine whose nozzle had just started to spin.

"HHHHHAAAAAAAAAAAAHHH!!!" William screamed which made the Gremlick look at him for the time being, this was its biggest mistake.

William was successful in making it lose focus of the defense bot and before the Gremlick could even do anything.

A slow sound projectile came right at it with the speed it could not even anticipate.

KUUUUFFGGGG!!!

The Gremlick was caught off guard, and it screeched as the arrow struck true, ending its threat before it could reach the tower. 

William's eyes widened in amazement at the efficiency of his guardian.

"Looks like we're in business," he said with an honest grin, preparing for the message to pop in any time.

Yet the Gremlick was still not dead, it was hit right in the chest and blood came out of its mouth, while William was looking at the Gremlick, the defense bot's legs moved for the first time.

'HM?' William saw it going to the back at a good enough speed before he realized it too.

"Fuck!" William couldn't believe that he had forgotten about defending the back one more time even after having such losses before.

The defense bot reached the back and another Gremlick was there looking at it with fury in its eyes. 

Yet the machine stood resolute, its nozzle started rotating again and this Gremlick didn't risk standing silently like the last one.

The Gremlick pounced at the machine but William was right behind the defense bot and at the right time, without getting in front of the nozzle, William pushed it by the shoulders which made it back away in order to be on guard and attack again.

Yet the nozzle was so close to it that even William didn't realize that the defense bot had head shotted the Gremlick in a split seconds after the three-second loading time.

[+20 EXP]

[+20 EXP]

William sighed and patted the defense bot on the head satisfied with how good it was.

====

[Congratulations on completing the fifth wave!]

[You were the 1,200,456,300th to complete the wave successfully!]

[The wave completion reward is shifted to the tower]

[Detected 3 dead monsters- Convert to Tower Points? YES NO]

[Next wave in 3 hours! Be well prepared!]

====

'Fuck, I am not in the special ranking this time…'

William clicked on getting tower points for the two Gremlick corpses and saw the corpses becoming light particles and going inside the tower. 

[+3 Tower Points]

[+3 Tower Points]

'What's that?' 

When the corpse was gone, his gaze fell on something that was at the place the corpse was once at.

He went near it and observed it up close.

And the hologram appeared once again to help him know what the item that he needed to know about.

====

Fire stone

Common Item

If processed right, it can be converted into fire gem or fire dust. It can be used for many more processes.

====

William examined the Fire Gem in his hands, marveling at the unexpected reward. The holographic display provided valuable information about the newfound item, stirring his curiosity and imagination.

"Fire Gem huh?" he mused, turning the gem over in his palm. The potential for converting it into fire stone or fire dust intrigued him. 

'But what is the use? And how do I even make it into these options?'

William was having a hard time knowing all this so for the time being, he kept the stone in his pocket and moved inside the tower to get the reward for this wave.

He opened it quickly without any further ado and got 10 more Tower Points.

'Well, I am happy getting these points but what about some weapon for a change?'

On the other hand, the defense bot had properly shown its worth to William. He was reluctant to upgrade it right now as it was good enough.

'My whole focus will be on the defense for the tower, as for the offense… I can take care of that…'

With newfound determination, William approached the holographic interface and selected the +5 in defense upgrade for the Tower. 

The Tower Points dwindled further, but the sense of security it provided was well worth the investment. 

Just like that, 3 days had gone by...

William kept killing Gremlicks one by one and completing waves without much trouble. His vitality was also full now and there was no need to use anything inside the sacrificial tomb.

There were instances where Gremlicks, and some hounds came together. Yet with the help of the defense bot and him protecting it from getting destroyed, William was able to take care of each of them.

While he may not have been in the top ranking for a long time now, he had accumulated quite a lot of Tower Points and did a lot of upgrades.

The defense was upgraded four more times now which is the max he could do for this level.

The condition for the tower level up was already fulfilled yet William waited for everything to get maxed out first if it was possible.

With the defenses done, William now willed to get the attack bot too, and get the tower elemental affinity without even knowing if it would be worth it or not.

Yet the best success he gained in this time being was with some energy, the surprising thing was that… the energy was not mana but something even more unusual.