The Witcher: Grinding Experience as a School of the Wolf Witcher

In 1228, a veteran player of The Witcher transmigrates into the body of a witcher apprentice named Arwen Thyssen.

That year, the Northern Kingdoms are busy expanding their territories, their borders rife with warfare and conflict.

Monsters lurk throughout the mountains and wilderness. This should have been the witchers' busiest age, but the book Monstrum has destroyed their prospects.

Fortunately, Arwen awakens a class proficiency system, and killing monsters can also earn him mutagens.

[Drowner killed. Drowner Mutagen acquisition rate: 100%. Talent acquired: Underwater Breathing (White)]

[Dragon killed. Dragon Mutagen acquisition rate: 100%. Talent acquired: Dragon's Eye (Orange)]

What if he can't beat a monster? Then he'll grind experience!

[Apprentice Swordsmanship Lv1 → Apprentice Swordsmanship LvMax. Talent acquired: Blade Sense (White)]

[Starry Sky Meditation Lv1 → Starry Sky Meditation LvMax. Talent acquired: Divine Incarnation (Prismatic)]

Years later, war breaks out between the North and South, and the Northern Kingdoms suffer a crushing defeat.

"Here comes the White Flame Dancing on the Barrows of His Enemies, Emperor of Nilfgaard-Emhyr var Emreis."

Emperor Emhyr raises his head slightly, looking across the Pontar River at the black-haired, golden-eyed man seated high upon an iron throne.

The herald's voice rings out once more.

"Before you stands the Mentor of the Order of Witchers, Dragonslayer, Ender of the White Frost Prophecy, Peacemaker Among Races, Distinguished Graduate of Aretuza, Member of the Association of Talent and Art, and Ruler of the Empire of Kovir-His Majesty Arwen Thyssen."

P.S. A fanfiction of The Witcher. No familiarity with the original books is needed to enjoy it.