Connecting combos

Is there a certain rhythm when it comes to connecting combos? Im asking because I use Superman and i find it hard to connect his (Great Purge) with his (Super Breath) in a string with no break
Combo: X,X,X+ Down, Right, Y

The special move becomes part of the string, it can be input as early as you want. You don’t have to time it or anything. If the move doesn’t come out, it’s because you input it too late.

ohhh okay, i jjust find it really difficult. Because ill do X,X,X and try and put in the super breath right after and string it but i feel like im not fast enough. But i understand what you mean, its just really confusing because ill do every button correctly and nothing happens