第1节

Section 1

After traveling through time and reincarnation as a demon, he also has a master who claims to be a superior demon, Rias, who often attacks him at night;
Himejima Akeno, who is also a servant, always wants to reproduce with him;
In order to avoid physical exhaustion and to survive, he works hard to improve his strength.
Can you become stronger by signing a trade contract with humans? Then sign it!
Sakurajima Mai, the quintuplets of the Nakano family, the killer Yoel, Kato Megumi... all sign it!
In order to live a peaceful daily life with his harem, Long Yi, as a demon, said that he still needs to work hard, either to be "invincible" in the world, or to have no "enemy" in the world.

穿越转生成为恶魔，还多了一个自称是上位恶魔的御姐主人莉雅丝经常夜袭；同样身为仆人的姬岛朱乃也总想要和他繁衍后代；为了避免身体吃不消，更为了苟命，努力提升实力。和人类签订交易契约就能变强？那就签！樱岛麻衣，中野家的五胞胎，杀手约尔，加藤惠……全部签上！为了能和后宫们过上和平的日常生活，身为恶魔的龙羿表示还需努力，要么天下‘无敌’，要么天下无‘敌’。