Magic Rings (also known as Rings of the Art) enable you to save a game at special saving points. Rings can be found in various locations. There is a plentiful but finite supply of Rings in the game.
It is unlikely that the player will run short, unless they need to save very frequently for some reason. However, there is another use for Rings, which would run out the supply much faster: they can also be used as a means to Buy Advice.
The Save screen features a wide angle lens shot of the Nomad Soul in their current location
Be advised that Advice usually refers to the current mission, and not parts of it, so if there are multiple tasks that require completion, and one of them is completed, the game may well consider that the bulk of the mission is complete, and default to saying something equivalent to, "the player does not need advice at this time and should not ask".
A mysterious old man assists the Nomad Soul by offering use of Rings of the Art. The player is not told until the end whether this is an unknown person, or Matanboukous, or perhaps his apprentice, Assam.