I put the gear back together for my dual-claws character, now a level 83 duelist, and started joining random map parties. Bought a ring or two, too. But at almost 10 aps with dualstrike, I'm running out of mana all the time.
No problem, take out a couple of points, put into the two mana nodes right near duelist start.
Still running out of mana. Maybe 2% leech isn't enough, maybe now I need 4%. The difference is small but noticeable. So is the difference when I take off my amulet, the one with the 30 int and 30 max mana. Hmm...guess it's time to do math, for the first time in a year. Mostly I don't bother doing exact calculations for this game.
8.57 aps, divide by 3 for multistrike, multiply by 66 mana per cast, is 188.54 mana per second.
11.5k pdps, multiply by 0.02, is 230 theoretical mana leech per second, assuming 100% efficiency. Before the changes to leech, this was sufficient provided your max mana could handle it. Since there is a noticeable difference between 2 and 4, I'm assuming 100% efficiency is not the case, at least in the former.
690 max mana, multiply by 0.125, is 86.25 mana leech per second capped. Huh. Let's try that again, and this time factor in base and increased mana regen. 690*0.14=96.6, approximately 100.
Is that right? I'm losing about 90 mana per second, which drains my 400~ unreserved mana in about 5 seconds total. Yeah, that looks about right.
In order to reach the equivalent point, 14% of max mana should equal about 200 mana. Give or take. Thus, I would need 1430~ max mana to sustain this kind of attacking indefinitely.
I'm looking at about 420 base mana, excluding items. (581 mana at +32% without gear, and there's a flat +mana node at shadow.) The easily available mana nodes are 3 at duelist for +32, 2 at ranger for +16 but separated by Primal Spirit, 2 near point blank for +16, and 3 near Charisma for +32. Plus travel nodes. Total of +96%, with +100% mana regen. I'll still need about 700~ total base mana, or +260 from gear, which is unreasonable when one considers the rest of the gear requirements. This solution is also very skillpoint intensive. EB is much easier, if you don't mind finding endgame-tier ES gloves and belt. Assume rainbowstrides.
I suppose there's a good reason Exalton went soultaker on his offhand. Several good reasons.
Quick and dirty: Cyclone takes 131~ mana, so with a reasonably long cast it'll be sufficient. Reave takes 37~, so all of a sudden we're looking at easy sustainability.
edit: Clarity is probably the answer here, but I'm not going to math it.