Watching the battle between his descendants from a far away distance, Zekram's face didn't display any hint of emotion, however internally he was in awe at what he was witnessing. This isn't the first time he's watched Rias and Sairaorg fight, it just never gets old seeing how each fight is more intense and destructive than the next. A small part of him can't help but somewhat envy Runeas, while Sirzechs, Rias and Millicas are all his descendants like they are hers. It's the fact that her descendants who inherited his Power of Destruction, seem to have higher talent and potential than his own descendants of the Bael Clan.
Regardless, even if Runeas has more claim over those three than he does, they still count as his descendants so there's no need to dwell on minor envy.
Truthfully he's more than pleased with the results of Sairaorg's growth. He sees Sairaorg as the one who will lead the Bael Clan to greater heights in the future. However, he knows this is all because of Rias, without her Sairaorg would still be without the ability to use the PoD.
Of course Zekram has met with Rias on more than one occasion. After keeping tabs on the young Gremory since her early childhood, Zekram made it a priority to officially introduce himself to her once Rias was officially declared a Satan-Class Devil nearly a decade ago. He understood the biggest threat to his Great King Faction is not the Four Satans. He knows he can deal with them to some degree when it comes to politics if need be. It's not wise to allow them to have complete control over Devil society since it will result in him and his faction losing political influence in the Devil faction.
No, the biggest threat is Rias. The girl is a wildcard that can instantly flip everything at a moment's notice if she chooses. The only reason why she's somewhat held in check is to not make too much trouble for her brother Sirzechs. But he's no fool, he can see that Rias will not hesitate to destroy the Great King Faction or the Old Satan Faction if either truly gets on her bad side.
It may not be publicly known, but Zekram understands Rias is the one who actually holds the fate of the Devil faction in her hands. Evidence being how she convinced the Youkai faction to become allies with the Devils after decades, if not centuries of hostile tension between the two races.
By doing this, she effectively put heavy pressure on the Angels and Fallen Angels.
A move, which earned Zekram's respect, not that she hadn't already had it.
This is mainly why Zekram made it a priority to build a positive relationship with Rias. The last thing he needed was to bring her ire to the Bael Clan or his Great King Faction. He also stopped trying to cause issues for the Four Satans and sometimes cooperated with them.
"Enjoying the show Ancestor?" Zekram wasn't not surprised to see Rias appeared next to him. He's aware of her ability to clone herself.
"Yes, I'm also wondering how long you are going to keep prolonging the inevitable. The boy is strong, far stronger than I expected of him at such a young age. But he stands no chance against you Princess Rias." Zekram replied calmly.
Rias snorted. "Well of course he doesn't, no one in this world comes close to me, Ancestor. I've said this to you before." Rias' tone carried hints of pride mixed with arrogance.
"I'm well aware, which brings me to wonder." Zekram said.
"It won't be good training for Sairaorg if I end it too quickly. As strong as he is, they are still those out there who are stronger than him." Rias then looked at him. "You should train hard if you don't want another one of your descendants to surpass you in both skill and strength regarding our clan trait Ancestor." She lightly teased him.
Zekram scoffed, for a moment he was reminded of Runeas. "There's no point in competing against monsters such as you and your brother, Princess Rias. Besides, it would be inappropriate of someone of my stature to compete with his descendants. An ancestor is meant to be surpassed by their descendants in the end."
"…did you just try to flex on me by playing the humble ancestor card?" Rias chuckled.
"I don't know what you are talking about, Princess Rias." Zekram allowed a slight smirk on his face.
They continued to watch the battle in silence, the real Rias just deflected one of Sairaorg's attacks then grabbed him by the face and tossed him brutally into the ground.
Nearly all of Sairaorg's peerage winced at seeing their King get destroyed by his younger cousin.
"By the way, have you thought about my suggestion?" Zekram asked Rias.
"Yes and the answer is still the same, I'm not interested in becoming the ruler of Devils. At least not any time soon." Rias sighed, this isn't the first time Zekram has tried to convince her to take over the Devil faction as a whole.
She's currently not interested in dealing with the mess that will come with becoming the true ruler of Devils.
"I understand, it's only a suggestion after all." Zekram nodded.
"Then why keep asking me about it, Ancestor?" Rias asked, rolling her eyes.
"In order to prevent you from putting it too far out of your thoughts, in my opinion you are the next best choice to replace Lucifer-sama as King." Zekram said.
"Since when were you such a suck up? This isn't like the fearsome and cold Zekram Bael from the stories told to all Devils growing up." Rias teased.
"I'm just pointing out the obvious, Princess Rias. As for those stories, many stories hold both truthfulness and falsehoods." Zekram retorted calmly.
Rias nodded. "By the way, does Lord Bael still hold a grudge against my mother?"
Zekram sighed. "Unfortunately, it still gets to him that Venelana was naturally more talented than him, and has greater battle feats and reputation. During the Devil Civil War, your mother earned herself quite the fearsome reputation amongst Devils and other supernatural forces."
"Poor guy, he's so pathetic that instead of doing something about it. He held onto a worthless grudge for centuries and stayed weak. Is this the Head of the Bael Clan you're so proud of?" Rias mocked.
Zekram frowned. "Proud of? Hardly. If anything I'm waiting for the day young Sairaorg finally takes over. Now, if you'll excuse me I will be taking my leave. I've seen enough to know the boy has once again grown a lot more powerful. It was nice chatting with you again Princess Rias, until next time." Zekram nodded at her as he disappeared via teleportation magic.
"I still find it odd that I have a decent relationship with Zekram Bael of all people after reading all the fanfics about him. Luckily, I knew his canon personality was different from those old webnovel stories." Rias said to herself.
This clone of Rias was a shadow clone, so it disappeared into smoke, transmitting the memories back to the real Rias.