Inside the measurement center, Felix could be seen standing before a silver punching machine. The first test he was aiming for was his physical strength.

He cracked his knuckles while concentrating on the red pad. Then he struck it with all of his strength, putting his entire weight on the punch!

Boom!

The sound of contact was loud alright, but the machine still didn't budge. It simply did its job and started calculating the force packed in that punch.

Felix took a step back and lifted his head, glancing at the final result that was displaying a staggering 5000 BF!!

Appalled and astonished, Felix kept staring back and forth between the number and his fist, having a bit of difficulty believing the behemoth strength that his body was possessing now!

He knew that he had just received double the known enhancement, and a thrilled grin couldn't help but start to widen on his lips at the thought of receiving this enhancement after each replacement.

He recognized that as long as he keeps using the primogenitors' bloodlines, he would always have double the strength of any bloodliner in his level even the ones with superstrength passive boost!

With this, Felix could finally let go of his superstrength passive without feeling shitty inside.

Thank god, the primogenitors never fail to disappoint as with this double boost, Felix would still have 3100 BF even after he loses his superstrength.

Soon, Felix went to carry on with other physical tests, such as his kicking force, his movement speed, his weight, his body defenses against physical abilities and elemental abilities.

After finishing those tests, he checked on his mental defenses and realized that he was finally capable of defending himself from mental abilities used by 2nd stage bloodliners!

Unlike superstrength passive, which affects only the body, the enhancement after the etching process affected literally everything about Felix. This resulted in him finally getting some protection on his mind.

After spending one hour or two, testing multiple mental abilities on his mind from a 1st, 2nd, and even 3rd stage bloodliners, Felix found out that his mind was almost immune to getting affected by 1st stage bloodliners' mental abilities.

As for 2nd stage bloodliners, he was utmost protected from lower ends bloodliners but those at the peak, he was getting affected pretty heavily.

Meanwhile, for the 3rd stage bloodliners, Felix didn't manage to survive even the weakest mental ability sent in his direction.

With those tests, he now had a clear understanding of strengths and limits.

"Now to energies." Felix wiped his sweaty forehead as he asked, "AI, please widen the room to its limits and place down a dummy every hundred meters away from me."

"As you command."

The measurement room started to expand and expand akin to a cube getting inflated but retaining its shape.

The process didn't last for even two seconds before the white room was big enough Felix couldn't see its walls, even though his eyesight was enhanced immensely.

"How big is the room now?" He asked.

"25 square km." The AI added, "If you want the room to be bigger, you need to pay additional fees."

"No need, that's more than enough." Felix said while turning on his infrared vision.

Although his eyes were no longer belonging to the Jörmungandr's, his passive wasn't affected in the slightest as he unlocked the ability, not received it with the mutation.

However, after turning it on, Felix noticed a massive difference from before.

Instead of seeing everything in black and white, his eyes were actually showing him color like he didn't even turn it on!

But Felix knew that he had it on, as the red auras of the dummies were too hard to miss!

However, Felix didn't show any signs of shock as he already anticipated this to happen. He knew that most of the passives overlay or even merge unless they were polar to each other.

Felix's enhanced eyesight added with infrared vision was extremely in line.

"This is truly a hundred times better." Felix smiled in satisfaction as he always was bothered by the fact that he couldn't see colors when his infrared vision was on.

"Hopefully, the distance increased is good as well."

Not wasting time, Felix turned on his infrared vision to the limit, making the silver dummies in front of him start showing red auras one by one until he was able to see ten red auras in total.

Since those dummies had 100 meters separating them from each other, this led Felix to conclude that his new infrared vision limit was a whopping one kilometer!

"Not bad."

Quite satisfied by the result of his mental energy increase, Felix scratched his chin while lowering the distance gradually until his vision covered only 200 meters.

The limit increasing to one kilometer was quite good but Felix was more interested in knowing how well his mind would fare by having his infrared vision turned on in such a medium-sized area.

He was planning to keep it turned on while continuing to do his other tests and practices in order to check if his head would start aching after a few hours or not.

...

Two hours later...

Whoosh! Whoosh!...

Felix could be seen trying his best to swing the golden tail at the punching pad.

Alas, he kept failing to make the bulgier end of the tail hit the pad. He always ends up either missing its completely or hitting with the middle of the tail.

"Again!"

Not giving up, Felix backed away three steps from the machine. He looked at his tail that was waving playfully and order it to stop.

Unexpectedly, the tail did freeze stiffly. Too bad, before Felix could smile, the tail started to subconsciously move on its own again.

"You little shit." Felix cursed with his eyebrows twitching in annoyance.

His irritation was understandable as he spent the majority of those two hours trying to control the tail first before using it to strike the punching pad.

In every attempt, he wasted at least ten minutes until the tail finally stops moving. Thankfully, in this instance, he only tried 30 times in 7 minutes before the tail responded to his wishes.

Not planning to waste this opportunity, Felix immediately used a tail swinging technique, that allows the user to dish out the biggest force in one single swing.

Since he learned it when he was using the serpent tail, he was having difficulty getting familiar with positioning and the animation of the swing.

Adding to the fact that his tail was acting like a rebellious teenager, the technique never worked for the past two hours.

However, at this instant, Felix felt that he nailed his form for the first time in the past two hours.

He couldn't help but glance with a tingle of anticipation at the bulgier end of the tail, rushing fiercely at the center of the punching pad.

BOOOOOM!

The thunderous sound produced from the contact was loud enough, Felix's ears were hit by a visible sound wave and made them ringing ceaselessly!

Heck, Felix felt like he was hit with a sound ability as his ears were hearing nothing but the irritating ringing.

Yet, he wasn't that bothered by them as his eyes were bulging out of their sockets in disbelief at the end result of his strike.

6700 BF!

Felix's brain turned into mush at the sight of such a monstrous force, that could be produced only by a punch from a 4th stage bloodliner!

He couldn't believe that his tail mutation was stronger than both his fists and feet!

After all, his punch could at most dish out 5000 BF while his leg during the tests was only able to dish out 5700 BF at best!

"Now this is a f*cking mutation!" Thrilled and overjoyed, Felix laughed out loud while holding his tail in his hands, feeling the bulgier end, which was as hard as a diamond.

When he touched it before in the shower, he expected that it was going to be quite useful in fights. However, not in his wildest dreams, would he have considered that it would be the strongest part of his body.

Now that he saw what it could do when it had its potential brought out by him, Felix removed any thought of ignoring this lethal weapon and decided to do extensive work on it.

He understood that his tail from now on was going to be his main melee weapon!

If he didn't learn techniques and methods to utilize its strengths, he would genuinely be letting down the Sphinx!

Realizing now that his tail was extremely strong and even steady, an idea abruptly too root in Felix's mind.

Impatient, Felix let go of his tail and order it to remain on the ground. As always the first attempts didn't work.

Regardless, he kept trying and trying until the bulgier end of the tail was finally on the ground.

Seeing so, Felix swiftly lifted both of his legs, making himself rely only on his tail to carry his weight! Unexpectedly, It actually worked like a charm!

Heck, he didn't even feel pained or pressured by doing so, as the tail remained as steady as rock.

However, Felix was still finding it quite difficult to keep his balance, especially when this was the first time he was attempting to do so.

In order to get a better posture, Felix leaned back slightly while lifting his legs even higher.

Thud!

Alas, the moment he lost focus on his tail, it started to subconsciously move on its own again, making Felix lose his support and fall on his head.

"This might take a while." Felix said while rubbing his head.

"Sir Felix, the extra hour you added is about to end." The AI asked, "Should I add another?"

Felix thought about it for a second before shaking his head, "No need, I am done."