He's My Fiancée ! : I Went Back To The Past and You ! - Chapter 70 - 65: Full-fledge Preparation

Satou Shiki a Japan present-day university student suddenly one day he got attacked by a slasher when he open his eyes he was already transferred to another world’s labyrinth city. In that another world he who was awakened to do a lot of “things”.

After a god screws up and accidentally takes high schooler Shou’s life, he offers him reincarnation with a gift to make up for it. Shou asks to retain all his old memories for the new life. Shou is reborn as Will, a noble’s son in a world where magic use is common and involves knowledge of kanji characters. With all his memories, he’s a brilliant toddler, and when he experiments with magic, he finds that he has an amazing talent for it! What’s more, though he was smart but unloved in his old life, in his new life he has a mother and a father who both love him deeply. His future as Will is looking very bright and cool!

Fang Shen’s eyes undergo perplexing changes after being hit by thunder. The change helps him acquire inscrutable and powerful life-death eyes which are able to launch many functions like clairvoyance. With the superb and magical eyes, he can dominate the world.

- Description from Novelupdates

My reunion with her took place in the worst possible way.