Nil-cross

Nil-cross is a T-Spin Triple stacked on top of an Imperial Cross. The terrain pattern which could be transformed into this setup is a bit hard to detect. Althought it is hard to detect midgame, this setup could be derived from a few openers.

Generic Structure
The easiest way to detect this setup derivation is when it creates an Imperial Cross shape with one of the side of it has a single pointy piece right next to the kick hole. For the aforementioned terrain, instead of directly going for an Imperial Cross, player could deny the overhang and load up a Nil-cross for more firepower. Please do note that stacking a Nil-cross will make the user vulnerable towards enemy's spike due to it's height.

Opener Derivations
As mentioned above, a few openers have continuations towards this setup.

Gamushiro Stacking
Nil-cross could be made as a continuation of Gamushiro Stacking right after it's initial T-Spin Triple.

HeboMAI Spin
This is an opener occasionally used by Japanese player HeboMAI during his time playing Tetris DS. It starts with a T-Spin Mini (which was used to be recognized as a T-Spin Single in the game). This could continue to a Nil-cross.