One thing I’ve noticed very quickly in this game is that players can easily ramp up usage costs of their skills, but have very few means to offset that. I’ve noticed it makes several aspects of the game feel clunky where there is otherwise no problem, so I’d like to propose a few mana cost reduction affixes be introduced to the common affix/loot pool.
For example, my marksman is using Flurry Multishot on a poison build. With this set up, I have no real way to spec a “mana generator” skill and a couple attacks put me out of mana, forcing me to run around and/or wait for mana regen. The only way I have found to offset this mana cost, so far, is to use Drelkor’s bow which is not the spec I was aiming for. That, or respec to a puncture based build and employ flurry as a mana generator only - which is counter to the build I was hoping to achieve.
Rogue is one of the classes which has the most amount of options for mana regeneration.
Also there is always the option of gearing mana regeneration affixes.
You can use Sapping Strikes Passive (or even Mana Warp for particular builds) in conjunction with Shurikens, Cinder Strike, Puncture or Flurry as a Mana Regenerator.
Also Dark Quiver and Smoke Bomb offer mana regeneration capabilities.
I don’t want to spoil too much for you, but there are plenty of options to regain mana, rogue is certainly the most creative class in that regard.
Just discover them all.