Asia is ultimately left out of the fight for her own safety, leaving it down to Rias and Issei vs. Sairaorg and his Pawn Regulus, the Nemean Lion that was defeated by the original Heracles and turned into a mid-level Longinus Sacred Gear.
"So who do you think is gonna win this fight Keima-kun?"
"Hm, I wonder about that. I think Sairorg Bael is stronger than the Gremory. Isn't that right Azazel?" I asked Azazel with a knowing smile.
"Mah, don't leave out the Gremory team yet. I did train them after all. So I'm sure you will be surprised by this fight." He said with a smirk.
However, this isn't for long when all the arena sees who is the pawn of Sairorg.
"The Namean? How did we never notice this?" Said Azazel in shock.
"*Chuckle* You didn't even notice that huh." He look at me.
"Namean Lion?" Asked Komachi
"Namean Lion is a Lion that fights the original Heracles. After that fight, he turns to be a sacred gear by the God of Bibel." I answer her. She look at the lion with amazement eyes.
Elsie didn't seem to amaze by the lion. But she did seems surprise by the lion insight.
Regulus quickly incapacitates Rias and forces Issei to use the Phoenix tear to heal her. Even without the tear the fight initially goes in the favor of Issei who uses a Scale Mail + Queen combination to keep with Sairaorg and overwhelmed him by attacking his arm that was weakened by Kiba and Xenovia, by using a Triana combination of Rook and Bishop to greatly injure him.
"So that's the sacred gear balance breaker you talk about Keima-kun?"
"Yeah, it's only one of many variations though."
"You seem acknowledged about this Katsuragi." Said Azazel.
"You can say that but well, it's really interesting. So I study it as much as I can."
However when Regulus suggests to Sairaorg to 'wear' him in order to acquire the power necessary to defeat Issei, Issei insists that he goes through with it in spite of the fact that he's essentially throwing the match. Thus Sairaorg activates his Balance Breaker, Regulus Rey Leather Rex as he dons Golden Lion Armor, which causes Issei to note that he resembles a god in that form. The second clash between the two of them leaves Issei incapacitated and forces him inside the Boosted Gear.
"The lion also can be an armor?"
"Yeah, that's called Regulus Rey Leather Rex. His Balance Breaker." The two of them nod at my explanation. And continue watching the match.
There Issei only stood. I guess it's where he confronts the memories of the past Sekiryutei hosts and is able to finally break through to them by concocting a new chant, and assumes a new form called Cardinal Crimson Promotion, turning into a Crimson Armor with power to rival the Juggernaut Drive. And thus his armor change to be that of Crimson Armor. I guess it did look cool.
The resulting clash between the two Longinus wielders ruins both armors. I think this is the scene when Sairorg sees his mother because he just keeps moving and then suddenly stop. He stop there and just stood and not moving anymore. We can also see the lion looks like he cried.
Sairaorg is ultimately rendered unconscious while standing up declaring Issei and Rias the winners.
While it's itself didn't surprise me it did surprise Komachi and Elsie who didn't really think that the Gremory team can win.