Submarine

Submarine is a TSS → TSD → PC opener developed by Eternalaws and Not Kaiyon, given the name "Submarine" due to its shape roughly resembling a Submarine diverging into water. This opener can be performed with an early L/J in the first bag. This opener leaves a relatively clean and easy to downstack board state thanks to multiple donation methods in the second bag.

ZLO Variant
Z→S, L→O→J

L J Variant
J→Z, L→O

PC Chance - 93.33%
If you have a late I and/or receive garbage when going for PC you can opt for a TSS into Tetris.

OJ Variant
O→J, Z→LS/L→SZ

JZL Variant
J→Z→L

S Prop Variant
O→L

TSD Followup
J→S

The third bag TSD variant is only dependent on a J before S thanks to multiple helpful L spins.

SZ Non PC Variant
This pattern has a very high succession rate thanks to multiple alt formations.

Possible Followups
J→S/Z, L→O

L→S→Z, O→J

You can put a Z piece on the right to freestyle a TSD with basic stacking on the left.