>>1781502
Boosts and Event cards already are capable of being permanent or effectively permanent (oh my friend, holy night, melting memories, indiscriminate fire support)
A new card type needs to function in a categorically different manner from the existing types.
>Boost
Either self-afflicting or targeted effect.
>Event
A global effect or one that affects the table itself (includes board, cards, and all players)
>Battle
For battles only
>Trap
Play during standby, activate when landed on.
>Gift
Activated while held
>Unit
Not actually played, but brought into play by another effect.
With these in mind, you need to consider what other times or interactions even exist with cards, triggers could be setup to be when drawn, on discard, or any other game event such as upon KO, triggering specific panel types, etc. However that has a lot overlap with the Gift type.
Will be interesting to see what it's about, since the last time we got a new card type, we got several characters that cared about them in short order: Tsih, Nico, Aru