I won't use Cyrax Forward Kopter because it disables your ability to use Forward Throw, Kameo Moves, Meat Shield, Combo Breaker, for 1/3 of the match (24 seconds)
I use Jax, he gives Rain nasty HTB's, very good meterless damage, combos off back throw, forward throw does 21% for 2 Bars and allows side switch for 1Bar(16%), gives you midscreen 46% combos for a bar using Kara Jump Cancel Kombos to catch them with fully charged water beam. Kara Jump Cancels let you remove recover of EXDB1 and go directly into BF1 or BF4 or another DB1.
For the HTB setup and 40% midscreen with charges water beam you input: EXDB1xxF+R2, wait till you can jump, press BU+F[1](hold 1 =[1]).
Jump Cancel Kombo with F21:
Here's the Jump Cancel Setups:
There's a mix where you can put pool down behind them at the perfect distance and throw them in pool or hit with F32 for combo
They can armor wakeup so be careful and bait it or do a close whirlpool if they are Armor heavy, they don't get breaker if they Armor
; )
Throw into pool hard to armor, and you can do it just frame to jail it into throw but if they block low you win, if they jump you lose, if they press buttons, you win:
This one Breaks Armor but delay wake-up changes timing, you can react or read it and setup accordingly:
Here's an example of what you can do meterless with it, if you spend 1Bar each combo you get 40% each HTB setup but 30% 3 times is 90% plus what you took getting them in the corner:
If you are Zoning and want to cover both the sky and ground at once, Kara Jump Cancels do this for you:
You just input F21xxEXDB1xxF+R1, wait till it is about to hit to call Jax so it's the last available frame, this gives you enough time to input BF4
But input BU+F4 ( so B then U+F,1) you input it like your doing Water Beam (BF1) or Whirlpool(BF4)
"Input Shortcuts has to be ON"
Hope this helps you, this literally makes Rain twice as strong