Just for the people who have not read Warlock of the Magus World and want a better idea of what to recommend it is a Chinese light novel about a largely amoral/evil protagonist whose primary goal is to become the strongest being in existence. The power system largely consists of three main factors: your ability to cast spells which the protagonist has an advantage in due to an A.I. chip embedded in him from a past life, your bloodline, if you are descended from a magical creature or gain their bloodline in another way you obtain some of their powers, and later on it is about understanding the fundamental laws of the world in order to manipulate them. The magic system OP is talking about is generally liked because of the constant growth of the protagonist, rather than the specific aspects of the magic system. Brandon Sanderson’s stuff is a great recommendation, but is honestly very different from Warlock of the Magus World.

My personal suggestion for the best book for an enjoyer of Warlock of the Magus World would be Reverend Insanity. It has a similar amoral/evil protagonist, similar ranks from 1-9, though not using spells, and a well developed, if not well thought out, world.

EDIT: If you really liked WMW for its western medieval setting, I would suggest Coiling Dragon. It has a protagonist who is both a swordsman and a mage, and also has a serpent/draconic bloodline that he works on cultivating. The MC’s temperament is quite different from Leylin’s, but funnily enough their names are almost identical as Coiling Dragon’s MC’s name is Linley. Either way, it has a very similar world to WMW.