Excuse the necro thread.
I feel like this thread needs reviving though. There's an inexcusable shortage of information/surplus of misinformation out there about how to maximize this job's performance both in DPS and cooldown usage. OP should update or pass the torch to someone.
I threw together some helpful tidbits as an example that I've studied, Dark Arts and MP-to-DPS priority lists both for single target and AoE, and some sample single target and AoE bursts (not necessarily openers however).
Single Target oGCD DPS Priority - Dark Arts is treated as an oGCD for the purpose of Souleater
1. Salted Earth - 525
2. Dark Arts Carve and Spit - 450
3. Reprisal - 210
4. Plunge - 200
5. Dark Passenger - 150
6. Pre-Souleater Dark Arts - 140
7. Low Blow - 100
AoE oGCD DPS Priority (4 targets assumed) - Dark Arts is treated as an oGCD for the purpose of Souleater
1. Salted Earth - 525x4= 2100
2. Dark Arts Dark Passenger - 250x4= 1000
3. Dark Passenger - 150x4= 600
4. Dark Arts Carve and Spit - 450
5. Reprisal - 210
6. Plunge - 200
7. Pre-Souleater Dark Arts - 140
8. Low Blow - 100
Single Target Dark Arts Priority - potency gained from Dark Arts alone
1. Carve and Spit - +350
2. Souleater - +140
3. Dark Passenger - +100
AoE Dark Arts Priority (4 targets assumed) - potency gained from Dark Arts alone
1. Dark Passenger - +400
2. Carve and Spit - +350
3. Souleater - +140
MP Priority
1. Dark Passenger 4 target 884/600 - ~1.5 MP per potency
2. Dark Arts Dark Passenger 4 target 2652/1000 - ~2.6 MP per potency
3. Dark Arts Carve and Spit 1768/350 - ~5.0 MP per potency
4. Dark Passenger single target 884/150 - ~5.9 MP per potency
5. Pre-Souleater Dark Arts 884/140 - ~6.3 MP per potency
6. Dark Arts Dark Passenger single target 2652/250 - ~10.6 MP per potency
Basic safe rotation: Scourge - DASE/DE x4 - repeat
Time remaining on Scourge<Time remaining on Delirium + Blood Weapon coming off Recast -
Scourge - HS - SS - DE (BW) - HS - SS (DA) SE - HS - SS (DA) SE - HS - SS - DE - Scourge
-Allows two DA Souleaters without losing Delirium or Scourge.
http://ffxivrotations.com/1mo
BW on cooldown + Delirium not needed -
Scourge - HS - SS - DE (DA) HS - SS - SE (DA) HS (C&S) SS (DA) SE
-Allows two back-to-back DA Souleaters without losing Scourge, weaves a DA C&S in with no interruption. Delirium falls for just under 2 seconds.
http://ffxivrotations.com/1mp
Sample AoE Burst/Mitigation
(ShSk/Wall) AD (BP) AD (SaEa) AD (DA) AD (C&S) AD (DA) AD (LB) AD - HS (DA) SS (DD) DE - HS (DA) SS (DP) DE - HS - SS - DE - Scourge x #targets (BP) - repeat
-Proper use of Dark Arts Abyssal Drain/Dark Passenger/Dark Dance in conjunction with Blood Price + multidotting.
http://ffxivrotations.com/1mq