J1 - 30 - cancels into U and I
J2 - 40 - cancels into WJ and SI
J3 - 70 - cancels into dash, SJ, WU and WI
WJ1 - 120 (50/70) - combo extender, cancels into J3, U, I, SI
WJJ - 50 - low endlag, cancels into dash, SJ and WI
WJWJ- 120 (50/70) - knockdown
SJ - 100 - knockdown out of shield anti air
KJ - 40 - combo starter, forces forward momentum
U - 125 (25x5) - armored burst knockdown
WU - 160 (40x4) - inconsistet anti air
SU - 50 - slow shield breaker and combo starter with a little armor in the startup
KU - 140 (40/100) - three projectiles with no hitbox inbetween
I - 300 (50x4/100) - multihit projectile
WI - 250 (50x5) - multihit combo finisher
SI - 460 (10x16/300) - multihit forward limited range lock-on
Safe moves - J3, WJJ, WU; U can be safe in some scenarios
Whiff punishes - U, I, WI
Dash coverage - J, WJ, U, WU
Anti airs - WU, WI
Mixups - WJ can be used in neutral with good followup mixups between just WJ1, WJJ, WJWJ and U; both point blank and spaced U make it so that the knockdown doesn't hit, turning U into a combo starter
Combo routes - bnb - SU J1 J2 J3 WU KJ KU; juggle setup - after WJJ it's possible to follow their dash with your own or punish no dash with J
Shieldstring finishers - J1 U, J2 WJ, J3 L, J3 WU, WJ WJJ L, WJ U
Zoning - KU
Out of shield - SJ; U armors through pressure
Zone breaking - U
Reversals - U can armor through okizeme attempts if they don't use shield breakers
The one tool Ichigo Shikai lacks the most is a consistent zone breaker to punish projectiles and other ranged options, so whiff punishers can help him a lot