As I've mentioned before, you can do a whole lot of non-combat stuff in BDO. For those things, it really makes no difference what class you've chosen. Everyone can equally become a cook, or gather resources, or fish. But combat can be a very different proposition for each class.
With all that area damage, you'd expect that a Witch uses up mana like crazy, and this is true. She gets a single-target attack to steal mana from an enemy, which is very helpful. Especially when there's just one guy left standing after a big explosion that ate up my mana bar. She's also got an ability to both heal and restore mana, albeit small amounts, which can affect any party members as well as the Witch herself.
Many of these combat effects look amazing, as is the case with many of the visuals in BDO. I've been known to stop and just watch the effects while electrocuting a bunch of Orcs with a lightning storm, or freezing a particularly aggressive bear. Admiring the effects isn't great for XP gain rate, but it sure does look pretty.
|...and the corpses left afterward.|
Gear is important as well, as with most MMORPGs. My Witch is currently using the Agerian set, which gives her extra casting speed. It's also fairly light in weight, so she can move a bit quicker than someone in heavy armor. Of course, that comes with the trade-off of lower defense, so getting hit can really hurt. Dodging, slowing enemies, and knocking them down is essential against anything dangerous.
On the whole, I'm fairly happy with my Witch's combat abilities. The big area-damage effects are a lot of fun, and the class abilities are well designed to allow you to use them without much downtime. She dies a bit more than I'd like, but that's likely my fault as a mediocre combat pilot, more than anything in the class design.