Mage has a number of additional things that you can do with your character that are pretty cool. Here are some of them for Risus below.
Legacies
Legacies are sort of more specialized magical callings that mages can follow. They generally have a much more specific philosophy and attract a certain kind of mage; they also have things called “attainments” that are earned at certain levels of Gnosis that are sort of special powers that can be used without spending Mana or making a dice roll.
To join a legacy, a mage needs at least Gnosis 2, and attainments are gained at Gnosis 3, 5, and 7 (with a sort of apocryphal extra one at 9). Dice in a legacy cliché indicate firstly that the character has joined the legacy, and after that the next three are the attainments, presuming that the prerequisites of Gnosis and Arcana levels are met.
If a character wants to start their own legacy, they must be at least Gnosis 3 to begin creating their own attainments.
Dice in a legacy can be used to pull rank on other members of the legacy as well as be added to rolls for things the legacy specializes in. For example, a member of the Perfected Adepts could use her dice in the legacy’s cliché in physical combat and feats of athletics.
More information about pre-written legacies can be found in the Mage books, or there are also a number of fan-created ones written up online.
Familiars
Familiars are generally animals imbued with a willing spirit. The spirit then takes over the body and can assist the mage in their magely endeavors. They have their own dice purchased by the player.
Soul Stones
Soul Stones are pieces of your soul that you put in an inanimate object. They have an inherent and pretty awesome benefit that they give you bonuses within the sanctum where they’re placed to your path’s ruling Arcana, but they also limit the Gnosis that you can achieve. These are always purchased double-pumpable, and the number of dice is the number of soul stones you have. You can use it as a bonus only within your sanctum, but as it’s a huge bonus that’s pretty awesome if you’re cool with that.
Making soul stones, is, incidentally, always a sin against Wisdom.