actually there are 2 builds of gem-heroes
1 of them is the control deck (similar to lightbeat)
mine abuses Gemini Spark, Citrine and Ruby
and the 2nd one is the fusion spam (the fun deck)
i have not been working on this build yet, cuz its in my opinion very hard to make.. combining: water, light, wind heroes + a decent amoun of gem-knights + the right fusion cards (fusion gate might do the trick) + traps... and i havent even talked about staples 0__0'
you should ask yourself which one you wanna build.. in my opinion pure gem-knights are the best:https://imgur.com/8vunw , but yeah pretty mainstream