Proposal:
Phantom magic is a lost magic with spells that phase through walls and other players’ attacks. They can’t be cancelled out through clashing, but they can still be blocked. It can create any normal spell types, but none of the attacks collide with anything except players and NPCs. Dispelling magic, reflector magic, and shatter magic can still interact with phantom magic like they would with any other, so they are the main exceptions. If any of the magics that can potentially stop or alter the course of a phantom projectile fail to do so, it will simply phase through (which also means the opposing projectile won’t be cancelled out like it normally would). If two players both use phantom magic, it will clash like normal.
Minor Details and Stats:
The magic could have a transparent, glowing look (similar to light or plasma, but with a fainter glow). Its color could be white, light green, or light blue (whichever fits best). It would have no destructive power, as it just phases through the terrain and structures (even if an explosion is used). Its damage and speed would be slightly below average to compensate for its unique ability.
Why This Should Be Added:
I feel like this lost magic would be a good fit with the others, as it has a unique ability that sets it apart without being too crazy. As stated previously, this magic can still be blocked, and some lost/primordial magics can still interact with it, so it stays balanced. I know there have been a few lost magic ideas recently that weren’t a good fit for the game, so I put a lot of thought into this one.
TL;DR:
Phantom magic is a lost magic type with spells that phase through everything except players, NPCs, other phantom attacks, and magics that can disrupt other magic attacks (dispelling, reflector, and shatter).