Mushoku Tensei: Isekai Ittara Honki Dasu, Kenja no Mago Recommendations
1) Both of the main characters die and are reincarnated in another world.
2) Both are reincarnated into a fantasy world where magic is abundant.
3) Both have memories of their past lives.
3) Both become some of the strongest magic user's in the world.
4) Both are interesting, funny characters.