What's left of these witchers after the Day of Fire, the decimation of the school by a fire elemental while escorting a royal caravan across a dessert, can be found in other keeps.
 
BONUS PROFICIENCY
At 3rd level, you gain proficiency in alchemist’s supplies and learn additional potion recipes, allowing you to replicate any potion in the DMG (but not oils). Cross-reference the potion’s rarity with Witcher Alchemy to determine which level you must be to craft a given potion.
 
ACADEMIC MONSTER LORE
At 7th level, whenever you encounter a monster for the first time you may make an Intelligence (Investigation) roll against a DC equal to 5 + the creature's CR. On a success, you learn one of the following: the creature’s name and what category Witchers classify it as, the creature's damage immunities, damage resistances, condition immunities, damage vulnerabilities, or one special trait. You decide which of these you are attempting to learn after you roll.
 
ARCANE SENSES
At 10th level, when you use your medallion to sense magic, you gain the full benefit of detect magic, you can sense whether a creature has the ability to cast spells and whether that ability is trained or wild (a source), and you can see invisible and ethereal creatures until the end of your next turn. Additionally, at your DM’s discretion you may receive prophetic dreams.
 
SIGN MASTERY
At 15th level, after three rounds of combat you recharge a Sign automatically and you can cast a Sign as a bonus action. Once you do, you must wait for another three rounds of combat to pass before you can use Sign Mastery again.
 

School of the Manticore Maneuvers

High flight
(requires Manticore wings mutation). When you move, you can expend one superiority die, rolling the die and adding the number rolled to your movement speed.
 
Perspicacity.
You can spend a superiority die to examine a creature you interact with as a bonus action. You gain a bonus on Wisdom (Insight) checks to gauge that creature’s motives and identity equal to the number rolled on your superiority die.
 
Revealing Strike.
When you hit a creature that can change shape, phase, or turn ethereal, you can spend a superiority die to deal extra damage equal to the number rolled. The creature’s true shape becomes briefly visible, and for a number of rounds equal to the number rolled the creature cannot change shape, phase, or turn ethereal.
 
Sign Strike
(requires Aard, Axii, or Igni sign). When a creature fails a saving throw against your Aard, Axii, or Igni sign, you can spend a superiority die to deal extra damage of the corresponding type (force for Aard, psychic for Axii, and fire for Igni) equal to the number rolled on your superiority die.