Argh, okay, so I've learned to deal with mash C with a well timed Hell's Fang but 5D is still shitting in my coffee. It completely controls the game. It is the first thing that comes out and is usually the opener to the combo that kills me.
When I run in from the ground, Instant Barrier Block into Hell's Fang works... sometimes. I don't know if it's because I'm too far away or too slow, but he can immediatly mash out another 5D or Ice Car. If he Ice Cars, I can 5B it, but if he mashes out another 5D, I'm dead.
I can't approach him safely at all. The only time I get in is if he makes a mistake or I manage to bait out a 5D and have time to counter attack. I tried the double jump with run momentum, but it is extremely difficult to do without accidently air dashing, and when I do pull it off, I usually overshoot him completely and the end result is we've simply switch places. Or he just uses that backwards ice spike thingy while I'm midair.
This is 100% my fault. It has to be. Somebody go into training for me and have a friend just sit there and 5D all day. Lemme know what I'm screwing up here.