all range b3 rain god sub zero combos:
mid screen: f21/b3 bf1 cancel b3xxrain god, forward dash b3xxfreeze, micro backdash bf1 full charge, ji243 1xxdb3
corner: f21/b3 bf1 cancel b3xxrain god, f21xxfreeze, bf1 full charge, j32 s1xxdb3
People really hate holding block on wakeup in this game, and Rain's meaty options don't seem stellar, so I've been occasionally ending my Janet combos (1x then 3x Janet routes) or sub zero freezes with bf1 full charge into whirlpool. Don't go for the htb since its pretty much fake, whole point of this is to guarantee 2% chip and oki, armor breaking if you time things right. You are pretty much guaranteed 114 bf1 cancel for plus frames, and the guaranteed chip basically makes up for any combo damage that you had forgone. With Janet, whirlpool + 114 chip will likely do more damage than any ender like j142 since she scales so much now.