To defeat his enemy, then conquer their women.
This was probably the best way for him to become stronger.
While the morality of this method was questionable, his opponents wouldn't care about their methods, so he could only ignore his morals and just fight.
Still, as he slept with the two most famous heroines in the story, he gained many extraordinary abilities.
[Congratulations, you have received "Business Mastery," "Hakoku," and "Mirror Lion."]
[Congratulations, you have received "Crazy Diamond," "Biology Mastery," and "Surgery Mastery."]
Those were the rewards he gained from Rias and Asia.
Suddenly, he felt that there was no need for him to work and he could spend all of his time sleeping with women; then he would become powerful. Still, even if he had such a wish, he knew that it was impossible to realize, especially when there were many individuals who wished for him to die. However, it was impossible for him to die as he couldn't die, so what did they plan to do?
He wasn't sure, but as they planned to mess up his life, he would also do the same.
However, before that, he was going to check his rewards.
Like others, when he slept with Rias, he got three rewards, which were "Business Mastery," "Hakoku (Warrior Nation)," and "Mirror Lion."
There was no need to explain much about the "Business Mastery" as it allowed him to master all the business practice and knowledge. Right now, with this knowledge, he could master the economy and wealth of everyone in this world.
Still, it has been a while for him to receive such a reward, especially when all the rewards he gained would make him stronger, so this was a good thing.
However, even if he gained rewards that made him stronger, he was also fine with it, and as expected of Rias, the last two rewards that he received from her were amazing.
Hakoku was a fighting technique from a Giant Race in a certain famous work. By using this technique, he could use and focus all of his power within his weapon into a single attack, destroying and decimating everything instantly.
'If I'd had this technique before....'
If he had this technique when he fought against the Great Red, then he wouldn't have been so desperate to develop his techniques and abilities to the limit. While he had many fighting techniques, such as "Boxing Mastery," they still lacked an impact and destructiveness compared to this fighting technique.
Frankly, if he had to fight, he wanted to end it instantly instead of a long fight where he had to be in pain for so long.
In other words, this technique was perfect for him.
Yet, this wasn't the end, and he got the more perfect ability for him.
Mirror Lion.
It is an ability to enhance and increase the efficiency of any weapon he holds by a hundredfold.
If he gave an example of how this ability would work, if he held a normal stick, it would have the same destructiveness as the legendary stick of Sun Wukong, Ruyi Jingu Bang. Then, in this case, he held his Star Buster Star Blaster, a planet, or this world would be destroyed.
"If I get this ability before..."
Riser lamented as to why he didn't sleep with Rias before he fought the Great Red. Even now, he still remembered how each of the smashes given by that beast was enough to kill him instantly, as each of them had enough power to destroy a planet, but now, he could do the same even without the power of the Great Red inside his body.
At the same time, he felt everything was so ridiculous.
When he thought that he had become powerful, suddenly, someone was above him. When he was above that someone, there were some beings that were even more powerful. Moreover, this was impossible to stop unless he saw the creator of the world.
Suddenly, he realized that when he was so ignorant before, everything was so happy, and now, he couldn't since every day was hard work.
At the same time, he also understood why Sirzech decided to entrust everything to Issei. Unlike Sirzech, who had hit the limit of his power, Issei was full of potential, and his growth had always given everyone a surprise. Moreover, along with the protagonist's halo and the power of the Red Dragon Emperor, there was no doubt that Issei would become powerful.
In the future, Riser wouldn't be surprised if somehow Issei gained the power of the combination of Ophis and the Great Red, turning him into the most powerful being in the world.
Yet, that was in the past, and from now on, this is his story.
Still, his explanation of his rewards hadn't ended. He hadn't explained the rewards he got from Asia, after all.
However, he had to say, the feeling of Asia's first time still lingered in his mind.
Her sweet cry, soft body, and docile, obedient act were vivid in his mind.
Riser thought that he had done a good job and knew that Issei and Diodora would be happy when they knew that he had made Asia feel happy.
"..." Issei and Diodora.
Nevertheless, the rewards he got from Asia were quite good, and similarly, he also got knowledge-type rewards, which were "Biology Mastery" and "Surgery Mastery."
The "Surgery Mastery" aside, which was practically easy to understand, he felt like the "Biology Mastery" was more interesting.
There were many beings in this world, including dragons, gods, devils, and many others.
With this "Biology Mastery," he understood everything about them. Not in the sense of personality, but their physicals were clear to him, whether it was their advantage or weakness. He understood all of them.
Still, he had to say, those two rewards aside, the last reward he got from Asia was somehow as expected.
Crazy Diamond.
Yes, it is that Stand that comes from the work that often shouts, "Ora! Ora! Ora!"
He got the Stand of one of the protagonists, Crazy Diamond.
This reward was somewhat unexpected as he knew how brutal the Crazy Diamond was, but when he thought about the ability of this Stand, he felt he understood why he got this reward from Asia.
Restoration.
This was the ability of the Crazy Diamond.
It was also part of the time manipulation ability, which was, no doubt, powerful.
The ability of the Crazy Diamond was to restore objects or organisms through touch.
It can repair damage, heal injuries, and revert chemical changes and complex structures to their raw components (e.g., a plate of spaghetti back into its raw ingredients). It may also fuse objects, for example, a person with a rock.
It is somehow quite similar to the "Degrenate" skill that he used previously.
However, Crazy Diamond's main ability was to restore, so in case someone was heavily injured, he could restore them to the state where they weren't hurt.
However, even if this ability was powerful, it had a limit, and that limit was that this ability couldn't restore his injuries. It can only be used to restore others.
While this ability was brutal, it was also gentle as it was born because one wished to help others.
Yet, somehow, for someone as evil as him, this ability might not be that suitable.
However, it didn't matter since this ability was good.
"Riser-sama, is this the place?"
"Yes, this is the place."
Looking at the gloomy sky on the distant deserted beach, Riser thought that they had come at the wrong time.