The reason of Yue Yang's surprised is not because of his inherent skill: Anime Gacha System since he already know about its existance beforehand.

Yue Yang's surprise is because he possess 2 more inherent skills, and this skills are inherent skills that belong to Otherworld Yue Yang when he arrive at this world.

[Counterfeit]: You are as cunning as a fox and as treacherous as poisonous snake. You are like an usurping chameleon who live under a camouflage. You are a facade, nobody can see through your heart. Your inherent skill will increase with your level. Your inherent skill current level is 1.

[Divine Vision]: You have eagle-like eyes and sage-like reactions. You are like a death god that see through living things's soul. You have an all-seeing vision that see through the world, so you'll be immune to illusionary or fake debuffs. Your inherent skill will increase with your level. Your inherent skill current level is 1.

'Damn, are this inherent skills like a default inherent skills for otherworlders? The Otherworld Yue Yang possess it, now it's my turn to possess it. Or is it just because this inherent skill originally belong to the Original Yue Yang, and both of me and Otherworld Yue Yang are just merely hitchhike him? In that case the Original Yue Yang is quite a rare talent despite being a canonfodder', thought Yue Yang rudely.

Anyway those two inherent skill will be very helpful to the current Yue Yang.

Counterfeit will help him conceal all his secrets since his secrets is too much of heaven-defying, such as his otherworlder identity, his cheat-like inherent skill: Anime Gacha System, or his terrifying guardian beast: Soul Devouring Beast.

As for Divine Vision, it'll help him to be able to indentify any foreign things in this world and help him familiarize himself in this world. It will also help him to avoid being cheated or scammed by other peoples. As bonus, it even make him resistant to debuff and illusions.

Above those two inherent skills were Yue Yang's inherent skill that he got from his request in his previous world.

[Anime Gacha System]: Inherent skill that make user able to possess Heroines, Equipments, Materials, Bloodlines, Skills, and other Miscellaneous Items from all kind of anime after spinning a gacha system by spending Gacha Points. User able to convert any amount of gold, mana, spiritual energy, pills, materials, and any other item with sufficient worth to get gacha points. Currently there are no additional features. Unlock the features by increasing inherent skill's level. Your inherent skill will increase with your level. Your inherent skill current level is 1.

"Hot damn! With this inherent skill, I'll be able to summon any OP hot chicks to help me conquer the worlds. Thousand Goblin Kings, Black Hell King, Scarlet Emperor; all of them will merely be a small fry before my army of OP girlfriends, Hahahahaha.....ahem ahem....", laugh Yue Yang with glee before he lower his voice since he don't want to make his little angel Yue Bing to wake up from her nap.

Anyway, he was very satisfied for possessing three inherent skill when every grimoire users were not guaranteed to possess even one inherent skill.

Yue Yang trying to open the second page to check his guardian beast.

"Holy Shit!!!"

Once again what he saw make him jump in surprise.

He already knew about his Soul Devouring Beast guardian beast since he already use it last night.

[Soul Devouring Beast]: A Special-type, level 1. A special beast category that connected to the user. It's able to devour other beings soul to grow the user's soul. The stronger the user's soul, the stronger Soul Devouring Beast will be. After devouring, user will be able to possess abilities, inherent skills, and informations that belong to the devoured souls without any side effect or complications. Currently could only devour souls that possess strength of level 3 [Hero] or below.

However, below his Soul Devouring Beast there is another guardian beast that originally also possessed by Otherworld Yue Yang.

[Phantom Shadow]: Special-type, level 1. You can control your own shadow. Each shadows will have half of your strength. Shadows can be joined together to increase their size.

The descriptions was much shorter compared to his Soul Devouring Beast, but it doesn't make it any less broken compared to the former.

Each Summoning Rankers could only have one [Guardian Spirit Beast] in their whole lives. Maybe some lucky one can also have two when they first contracted the summoning grimoire.

[Guardian Spirit Beast] can be called as Summoner's ultimate beast, their last defense, and their live saving.

As long as the summoners doesn't die, their [Guardian Spirit Beast] would also never die even if they were killed numerous times.

They would never die, never betray their master, and able to grow alongside its master without having to met other conditions like ordinary contracted beasts.

As long as the user's power increased, or that the summoning grimoire level increased, [Guardian Spirit Beast] would also be stronger.

Meanwhile, contracted beasts need many stringent requirement to be contracted.

They need to be contracted willingly in order to increased the chance of contracting the beast.

Summoners could also forcefully contracted other beasts by the means of violence in order to subdue them, but their loyalty at the start will be low. With low loyalty, contracted beasts will not obey summoner's order fluently and sometimes the contracted beast could even harm its own summoners.

The difference between contracted beasts and [Guardian Spirit Beast] is very obvious.

Unfortunately every summoners could only have one [Guardian Spirit Beast].

However there is an exception to everything, and that is Yue Yang's Guardian Spirit Beast: [Phantom Shadow].

With this [Guardian Spirit Beast], Yue Yang will be able to make shadows that will be joined with his future contracted beasts, and make those ordinary contracted beasts to possess the same quality of [Guardian Spirit Beast].

It was not different from possessing numerous [Guardian Spirit Beast].

The benefit of this is not needed to mention isn't?

He can have numerous undying beasts under his rules that will never die with high loyalty, and able to grow alongside their his growth.

And if this [Guardian Spirit Beast] was paired with his summoned heroines from his Anime Gacha System, hehehehe...

He'll have a powerful army of sexy bishojou that will never die.

Broken! His cheat was broken I tell you!!

Of course there is a disadvantaged to Yue Yang's Guardian Spirit Beast: [Phantom Shadow]. Compared to other [Guardian Spirit Beast], it need 10 times mana in order to summoned even just one shadow.

However, this disadvantaged is quite negligible since in the future he'll possess abundant of mana when he already grow stronger.

Moreover, when others could only summoned their beast with duration at maximum of 5 hours, Yue Yang could summoned his beasts with maximum duration of 10 days.

The advantaged obviously far outweighted the disadvantaged.

After Yue Yang finish checking his [Guardian Spirit Beast], he back to the first page in order to check wether he can try using his inherent skill: Anime Gacha System.