Kartika in Shingon

[Sherlock]

Is the Kartika (Tibetan trigug) used in Shingon or part of any deity's iconography there?

I've seen it in some anime and manga, I wonder if it's just them borrowing its use in Tibetan Buddhism.

[Seishin]

I have not personally seen it before, but that's not to say it doesn't exist.

Gassho,
Seishin

[WuMing]

I've never seen that ritual instrument in use in relation to any Shingon ritual. AFAIK, it is not used in Shingon at all. This ritual instrument is mainly associated with the Tibetan chod གཅོད (gcod) ritual and a ritual like chod doesn't exist in Shingon.