Naght Seiger Twin Blade

[presto11]

hi im an assassin from a low rate server, i think 100% non-edited

with

55+ bonus str
99+ bonus agi (maxed 190 aspd )
81+ bonus (high to catch up with 190 aspd )

im using

thanatos+valk+turgen Mes and whitesmith+hydra+phreeoni+lordofdeath(some enemies are hard to kill so i use this for stun/silence etc) Blade

what im planning is to buy me myself a Naght seiger twin blade, do you think its worth it? or not? the sad thing is it has [3] only, and its fire/water ( does it work with off-hand?) please please help me on what to do,

to buy or to not?

and how about my blade, im trying to switch with different sets of blade, what other cards can i use? thanks people.