There are a couple ways to do this. You could delay the 623D or if you don't want to do that, you can delay the 4D and make sure it hits in front of Ragna's legs so you can avoid needing to delay 623D. Keep in mind that when I say delay, it means 1-3 frames of delay. Very slight delay.
As for Bang, he's one of the harder ones because you need a combination of delaying 4D and delaying 623D. you also have to do neutral jump 8D for Bang.