so most of your mastery amulets are from water works you can also buy them with crowns if ya don't wanna farm for them. but let me just also say that cronus in tatarus drops exalted amulets those are pretty rare I ve been playing this game for a couple years now and have gotten 2 exalted amulets one was fire and I was lucky enough to get a exalted life mastery ammy and I only use that when I am a healer on my death char which I will say is quite the healer lol hope I helped
The basic ones have no level restriction so anyone can use them. You can buy them from the crown shop. They drop in game from the bosses in Waterworks and Tower of the Helephant, but they are extremely rare drops. I have only a few from hundreds of runs through these instances.
There are more advanced amulets that give mastery and minor stat boosts. They are only from drops in high level areas like Tatarus and Darkmoor.
1) Basic Mastery Amulets give you mastery in another school. They can be found in the crown shop OR in Waterworks. These are also NO AUCTION. These are the ones that go on half price sales a few times a year.
2) Exalted Mastery Amulets give you additional stats as well as mastery in a second school. They can be found in Aquila and are NO AUCTION. I can speak for getting 2 of these in Cronus personally.
3) Darkmoor Mastery Amulets give you shadow shield cards, additional stats (different from Exalted stats), as well as mastery in another school and are NO TRADE/AUCTION. These can be found in the gold key chest in part 1 of Darkmoor, and I got a bunch of these. Im holding out hope that eventually KI will come to their senses and at least make them bank shareable lol
There you go, the full list of what they are and where to get them