Yamcha’s 2H (⬇ + Heavy ) has crazy cross up mix up potential when you air dash or high jump in front of the opponent. His dive can go through the opponent if timed correctly.
[From Right Side]
Air Dash (Instant Air Dash, or IAD, is recommended) or High Jump ⮕ 2H ( ⬇ + Heavy )
Again, the timing is tight: it’ll switch your opponents guard causing confusion as the move is quick.
Also note: you can use 3H after IAD to make it easier.