Living as an old man in DxD

Fight with the Hero faction

They went Inside while straightforwardly Ophis went for the cookies while Kuroka told the peerage what going on. Apparently the Hero Faction, after their defeat in Kyoto, grew tired of following Ophis' orders as they sought to use the Infinite Dragon God's power for their own end, making a deal with Hades to use Samael in order to obtain Ophis' power.

Vali, learning about this through his own connections, sent Ophis to the Hyoudou residence as Ophis was interested in the current Red Dragon Emperor's growth.

Suddenly while partying the dimensions were trembling while magic was increasing a gap formed opening to reveal two figures It was Cao Cao and Georg

Cao Cao: Yo Ophis

While Cao Cao was talking Georg immediately launched fire magic at her which she negated along with that attack Cao Cao attacked with True Longinus but it Ophis remained Undamaged suddenly space Distorted it was then Vali appeared. Xenovia instantly deployed Durandal and went for Cao Cao

 Cao Cao: Such a fool you are 

 Cao Cao Immediately changed the Longinus to it's orb form destroys the sword and stabs  Xenovia

ORC: NOOOOOOOO

 Cao Cao: Hmmm Foolish hero that fell for the devil

 Cao Cao immediately sealed Rias and Akeno's power to prevent any counter 

Kuroka: We need to attack La fay Know:

Kuroka and La Fay attacked but failed as  Cao Cao redirected the attack by teleporting them in front of Asia

Issei: Draig now!!

Ddraig:[ Boost: Balance Breaker: Welsh Sonic Boost Knight]

Issei immediately sped to save Asia in time.

Reinhard was in a separated dimension as he observed the whole fight he had judged it wasn't time to interfere he then created a chair as he sat down

They were fighting a losing battle as the fight continued Cao Cao exchanged Georg with Siegfried and the Gream reapers arrive 

La fay runs towards the beaten-down Xenovia with Irina

La Fay: You need to warn the other factions I will teleport you to them

While Issei was fighting Cao Cao he used Cardinal Crimson Promotion

Ddraig: You need to get out of here Issei you can't defeat him yet

 Issei: I know but I can't leave them yet

Issei was exhausted with all the promotion he used plus many enemies had joined the fight it seems like this was the end of ORC Issei was fighting shall suddenly in between their fight

a void appeared from the void was an old-looking man

Reinhard: Damn I guess I got to take care of this mess

Reinhard extended his hand and muttered [ The Cane Of Sage] a cane of wood appeared

everyone in the battle felt immense power falling above them a huge portal appeared taking the entire mountains and lands into the underworld

Reinhard: This fight will continue here, but let's see how you can do oh Hero Faction. Come to me scroll of Reincarnation

A gigantic scroll appeared while all of a sudden gigantic thousand hands appeared from him but they instantly disappeared 

 Cao Cao: Everyone stops that old man

The Grim reapers started running towards the man but it was a too late zombie-like creatures made from the flesh of the dead devils  turned into monsters that give sheer terror to them they destroy each other

Reinhard: Come to me [ Eight Letter of Tathagat: Fifth Holy book]

 Cao Cao was feeling shivers using his orbs he attacked the old man but it was useless

Reinhard: You can't even use the spear true power you don't deserve it

The orb disappeared and appeared above the book of the old man.

Reinhard: I will teach you a lesson young one

Reinhard:  [Baekdu]

before he could even defend he was sent flying to the ground the damage from the kick broke one of his ribs before he could even fall Reinhard used [Bo-Bup] to appear behind him and went for [Spinning Top Kick] Cao Cao managing to defend still suffered immense damage to his face he was bleeding from his nose.

Reinhard: You are quite resilient for a young man

Reinhard: [ Golden Needle from Mystery Island] a giant  needle appeared piercing through the sky directly pressing Cao Cao through the ground forming a giant hole to the ground while Cao Cao was rendered useless Reinhard faced the next enemies 

Reinhard: Come to me [ Lecalicus] release yourself and devour them

Different from the original seven dragons appeared from the sword and devoured everything enemies leaving Azazel and the ORC shocked never had they seen a force changing a disadvantageous situation 

Siegfried and Shalba fleed while the Grimm reapers were devoured those who fled were met with Reinhard [ Zahard Style lethal Control skill-Comos]  rasing half of the underworld after the battle he used his cane and brought everyone back Rias and others were shocked but they needed to save Issei since he was poisoned with poison from Samael but they could see the old man carrying Issei

Reinhard: We meet again Young  Gremmory

The most spectacular fight in the underworld had ended