For a Master, I have some idea's but I'll have to iron them out. 

But it is going to be a Greek Mage by the name of Leviticus Masters. 

Fate Academy is about a mage school, where the first year students hold a Fate/Apocrypha type tournament, with a huge cast of Servants, being whittled down to 21 and then to 7 and then to 1. 

So like a huge scale grail war set in a edgier Harry Potter type boarding school.