it depends on wich difficulty mode u r playing actually...but i would recommend u to use TRICKSTER for the vergil final battle in all the modes cos its very useful.never mind abt getting SS rank.it might take some practice to beat him cos he teleports more often than the other 2 battles.i suggest u start with easy mode and then u slowly ramp up the level up to DMD mode....
even wen i fought with vergil3 the first time on easy mode,it took me 8 minutes to finish him off now i can do it in less than 1 minute...