With her unblockable bullet, she can create a no-win scenario with this setup.
C
2C
Full screen combo; if you have a large amount of BBQ, you can wipe out a chunk of health.
j.C
Grenade
Really annoying combo; create a bit of space; in the corner, you can make this safe with a j.M afterwards.
A
B2BCPositron Storm
Damaging 'get off me' combo.
(Special Ammo Loaded) C
A GrenadeLOAD ARMOR PIERCING SHELLCPositron Storm
With 5 bars, you can loop her unblockable bullet to death, giving Saki technically an infinite.
A
B2BC6CA LaserBBQB3C
sjc j.B
j.BC
Quick combo Saki can pull out; doesn't knock down and damage is eh but it's a start.
(C Bullet Loaded) A
B2BCommand GrabB3C
sjc j.B
j.B
j.C
66 BC6C
Saki's basic relaunch; with the right assist, she can reload a bullet.
World's Greatest Attack
66 BC6C
Only if Saki is facing the corner.
A
B2BCLOAD SPECIAL AMMO
THC CPositron LaserLOAD SPECIAL AMMO
3C sjc j.B
j.B
j.C
C LOAD SPECIAL AMMOC
This example uses Polimar but honestly any character works; they have to wake in block stun, which is a free unblockable bullet, which means Saki gets all the privilege as usual.
C Ammo
2A2B3C
sjc j.B
j.B
j.C
5C LOAD SPECIAL AMMO
Assist 5C Load C Bullet
66 5B3C
sjc j.B
j.C
j.C
5C LOAD SPECIAL AMMO
Assist 5C POSITRON STORM
Look at how fair this character is. Again Polimar is the example, but this should work with everyone except Viewtiful and Yatter-1, which maybe you can do with some finessing. As long as Saki has meter, you're dead.