 If you liked
Sekai Saikou no Ansatsusha, Isekai Kizoku ni Tensei suru
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 ...then you might like
Ore dake Level Up na Ken
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Even though "Sekai Saikou no Ansatsusha..." is an isekai type, while "Solo Leveling" veers more toward sci-fi/dystopia, both focus on their protagonist's journey to increase their fighting abilities. Additionally, both protagonists take a similarly cerebral approach to plotting out their evolution.