My queries abt the kylin set effects

Currently i have the frozen kylin set, whose two effects have hlped me alot in PK with cruses since the literal 'frozen' effect which stuns any crusader who dared attk or stun me for five secs buys me some time whilst im stunned while the slash protect ffect has protected me many a time from One-ISes XD

now im wondering what's all this hoo-hah abt dark kylin and eternal kylin and corp sets being so 'good' while frozen sets arent preferred T_T, save from what I know, its just more/different effects and better glove and boots stats. i've heard it give better attk and overall stats but before i go forking out for the first time in my life here, i wanna know exactly the 'awesome' side of the eternal and dark sets exactly. like, what effects and 'bonuses', if any each set has, thks in advance.

Also, im wondering, if i upgrade my frozen set to eternal, will the forge be kept or do i have to reforge again?

and i've seen ppl sellin kylin sets (unique ones like dark and so on) so is it tradable when fused or must i use a card?

well i'm an ss, so wat r the effects of dark or eternal set then? And if i were to upgrade my existing kylin set which can only be done by donaters since there is no card but just dcs as the payment for the npc, will i lose my forge in the set or does my new set now contain the same forge?

You only need 1x Gem transfer card as long as all 3 parts belong to the same set. But in your case, its easy to reforge them yourself since your gems are not very high level.