yeah this is a good explanation for it here.
i’d keep your crystal file honestly. just get light when second awakenings come out if you like crystal enough. crystal is pretty okay on conj, and light is better.
Light is good on Conj. Light is good with Crystal.
Crystal is okay on Conj. Crystal is alright with Light.
It’s a web. They all interconnect.
Acid is best if you want a little bit more damage, Light for more speed, and Lightning/Ice (probably Lightning) if you have Sunken items.