SS should be your natural choice since you'll be force crit'ing it.
I tried SS the other day... and still not impressed with Rudra's damage. (4k on yearner with 300 TP).
With the FM requirement and a flourish that eats all stored FM, Rudra is really not that good of an empy WS.
Do you by any chance sub the magian TP dagger?
As for the using the Finishing moves....If you're just doing Rudra onces... just need 1 FM (2 if it's consider a two hit WS which im still unsure on that)
As for me I just have a macro that does Climactic Flourish then Rudra right after....
And since my step macros have presto before them either way... I'd have 2-3 FM which is fine for one rudra
Now....if you want to make Darkness out of it.....that's a different story...
I have two different Darkness macros.
1. Rudra's Storm > Evisceration (could use pyric instead but the aftermath can't is just nice)
2. (Already have FM on me) Climactic Flourish > No Foot Rise > Rudra's Storm > Reverse Flourish > Rudra's Storm.
Note: Due to the TP dagger except for maybe the first rudra i do......@100TP it's really 200TP
Now mind you It's rare i can pull #2 off in a group situation with everyone spamming stuff but if I'm able to do it.....it'll do nice damage in abyssea right right stuff.
I don't attempt to do Darkness as much in party situation but low manning I take that to my advantage.
I'll try to screenshot a picture but when I did Nonno (mandy nm in Abyssea - Misareaux) about a week ago, with Red Curry Bun and I believe Stalwart Tonic I did over 15k damage with Darkness #2 Which for DNC in general.....rather amazing.
No idea if Mandy are weak to dagger or weak to the Darkness Elements but it was nice to see that. Now I don't do that much compared to like thicker NMs like say Alfard but Rudra opens up DNCs damage output in abyssea......outside probably not so much.....
Compared to the others Rudra's rather meh by itself...