No problem! Will wait until the game has a proper gamepad controls, good luck with implementing that! ^^
I used the standing normal, crouching normal and jumping normal attacks. Neutral has a long startup with wide range and is good against Big-the-Cat creatures. Aerial up-slash is too hard to execute on keyboard, so i rarely used it. I can suggest to add an aerial down-slash to hit enemies underneath from above.
You can check out my game for controls and combat mechanics (please rate), it may also help. For example, Combo-to-death can be fixed by performing pushback the similar way I did in my game: it pushes away the target character and if there is a wall and no space, push the attacking character away from target instead. If it is too complicated to implement in platformer - push both characters away from each other at 0.5 of desired distance. After repeating the attack 3-4 times, it will whiff because of it becomes too far away.