Had a little help with this but neither of us know much about fuinjutsu stuff so hopefully this looks good!
Name: Seal the Seal with a Seal! (SSS)
Rank: (E-S) B
Elemental Affinity: no
Notation: Secret Technique
Lore/Flavor: Sayaka was worried about her seals getting stolen so she came up with a way to make that harder. That way she can use them more without being worried about theft!
Description: This is a seal that is put on top of another seal. It hides the seal it is covering but doesn't prevent it from working it just can't be understood while the SSS seal is on top of it. If the SSS sea is tampered with it detonates like a weak explosive tag (rank "D" damage) but since it is "integrated" on top of the other seal this explosion erases it!
Drawbacks: The effect of this seal is not immediately apparent but if someone has seen it in action they could develop a custom higher rank technique to undo it probably. It is really just to keep people from stealing FTG which seems really easy!
So long as you understand this still interacts via Hybrid Checks (Fuuinjutsu Skill Level + Wisdom, opposed by the same from the individual analyzing it) this can be approved.
_________________When skeletons live inside your closets
They can make you fear
That no one will hear us sing our songs
The truth is relevant, but not for long
This love is our downfall
But the hurt's not going away
I'll bury all the past
Everything in its place