I use Perdu Sword, but only because I don't want to spend the time to unlock Subduer, and I'll never see an Algol.
Actually looking at the stats... Subduer
D85 Delay 444(7.4s) DPS:11.48 TP:11.3 (9 hits) (66.6s to 100)
Crit +6% Perdu Sword
D84 Delay 456(7.6s) DPS:11.05 TP:11.8 (9 Hits) (68.4s to 100)
Acc+5 Atk+12 Algol
D85 Delay 489(8.15s) DPS:10.43 TP:13.2 (8 Hits) (65.2s to 100)
TA+3% Atk+3 Add Effect Fire Naglering
D85 Delay 501(8.35s) DPS:1018 TP:13.6 (8 hits) (66.8s to 100)
Acc+4 MAcc+3 Atk+20 (DRK only)
Looking at those, its pretty clear Subduer is the best, but close behind it are Perdu and Algol. And any x-hit build you can do with Sub you will be able to do easier with Perdu (slightly).
Adding /SAM (+15) and Rajas / Brutal / Chiv (+5/+1/+1) lets redo the math with +22 sTP.
Subduer 11.3 * 1.22 = 13.78 (13.7) 100/13.7=7.29 (8 Hits) 59.2s till 100
Perdu 11.8 * 1.22 = 14.39 (14.3) 100/14.3=6.99 (7 Hits) 53.2s till 100
Algol 13.2 * 1.22 = 16.10 (16.1) 100/16.1=6.2 (7 Hits) 57s till 100
Nagle 13.6 * 1.22 = 16.59 (16.5) 100/16.5=6.06 (7 Hits) 58.4s till 100
Seeing that... with easy to get gear Perdu can get a 7 hit where sub is still on 8 hit. Sub would need +26 in sTP, or 4 more from -somewhere- (food can give 6 but pasta is expensive for playing around). Algol also needs +26 sTP to hit 6 hit. And Nagle can hit 6 hit with +23 (so throw europhic ring in there).
Still think Sub would win on basis of DoT + Crits alone, but Perdu is a close second (Algol will win if you can get +26 in sTP).