Well i just made this superior build over my other guide i once made!
So if you wanna become a dex knight you should have on lvl60
str40 (if you can't afford strentes you should have 50str)
sta60 (if you can't afford strentes you should have 50sta)
dex63 (well this is pretty much it

)
int 15 (the obvious)
Equips you should have if you can afford atleast
Gaurdian Big sword+3 (at lvl70 you switch to Historic Big sword)
2 stente+1
2 mightier+1
Recorn set +10 if possible or just +3 or higher
You will have around the 60-70% attspd then
Reason for Recorn set and not the lvl62 knight set is + attspd ^^ Recorn set gives something like +25% attspd ^^ and why GBsword instead of GAaxe is cause the sword gives +HP, is faster and gives +30def.
So now you keep editing to 80dex (you don't need more) So after just go pure Str ^^ You don't need more sta then 60 cause of the defence of the armors and the nice HP bonus knights get after job change^^
on lvl70 it is a must to switch to Historic big sword cause it gives +10% attspd and if you can get a non upgraded buy alot of shining orchalciums and make it a ultimate +3 or if you have money left buy alot of Sprotects and try to get it as high as possible ^^ You will need this sword till lvl105

"
Also try to get your Recorn set to +10 cause you will also need that one till lvl90 or 105
So build will be as followed after lvl70
Str XX
Sta 60
Dex 80
int 15
Also you can switch your strente and mightiers to strentes +2 and mightiers +2 after lvl80 :P but i doubt anyone can afford them at that points >.> they cost 40mil for strente and 60+mil for the mightier >.>
Why would you use HBsword till lvl105 ! cause of the attspd bonus

Why Recorn set till lvl90-105 cause of attspd bonus :P (i think the lvl90 set also gives attspd bonus but not sure so it could be the lvl105 set to

)
Tnx for reading this "Omg how bad" and enjoy finding out what it all says cause i doubt the grammar was any good :P