Manga about a person who goes into the past

I read this in the past and lost it, the main things I remember are

• Character dies and gets placed into his body from a few years back
• the world was normal but then turned into a game where the players kept their progress
• Character has a sister that he takes care of
• Rejoins the game knowing the secrets and gets mastery 100% on every weapon to unlock "Ki" while the other players think he is stupid for not level grinding
• Is in color