honestly you can do good with any magic if you have the skill, just improve your aim, improve your blocking, improve your movements, just keep improving and eventually the only thing holding you back is the fact other magics can do more with less effort.
its a slow magic, so hug the opponent. dont stay too close though. crystal is still a little bit too fast to get next to people with, and not as much dmg output compared to gold/iron.
predict landings. a good thing for all magics in pvp. aim down on the ground to where somebody will land.
get used to the magic’s speed. this will help you with predicts in the air.
if you have god gamer ping, do a stamina jump (t jump) on your magic high jump. extra height. good mixup. can do this with all solid magics.
otherwise just a simple case of git gud. crystal is atm an extremely shit magic, so dont expect to become extremely good at it. i always feel like im doing amazing landing all my hits just to get destroyed soon after. just learn to suck it up and move on.
invest in;
a full hard wiz set (pants, shirt and hat)
hard defense amulet
hard power amulet
also known as a 1022 build (because you have 1022 health wowie!)
i use this build for all my files. it works with pretty much every magic.
for shields, just use a heavy woj or a hard vast.
like i said before, semi-hugging.
but all magics also have that element of “you choose your playstyle”. get good at your way of playing.