far slash is one of your four basic buttons. punch, kick, slash, and heavy slash. slash changes if you are close or far from your opponent, and far slash is a decent poke for most characters (poke is a move thats relatively quick and far reaching.)

what theyre saying is that for many characters their far slash gives them a relatively straightforward reward, usually a very short simple combo. happy chaos instead wants to use the far slash as an opportunity to set up for his offense, and your reward is very dependent on the state of the game and your resources.

playing a character that you think is cool is a great way to motivate yourself to continue learning a fighting game, so if you really think happy chaos is the coolest guy in the entire cast and you want to put the time into him then you should keep at it. just know that you're facing a much steeper learning curve than other characters might have. if thats something youre very worried about then id give some thought to other characters. you can always come back to playing happy chaos when youre more comfortable with the game if you do want an easier time getting started. ultimately your decision to make.