Playing through second time with an arcane build, really disappointing. About the biggest source of non physical damage I've done is with tonitrus, and I could do that on any character. I haven't gotten all the items yet, but most of them are extremely useless.
The beast roar is kind of nice when you're surrounded, otherwise tentacle claw has a long cast time and mediocre damage (and also a slow recovery), tiny tonitrus does mediocre damage for 6 QS bullets, empty phantasm shell's effect isn't noticeable. Haven't had a chance to use the gloves or a call beyond, but everything seems extremely mediocre compared to the magic builds in dark souls 1/2. Even the arcane stat scaling on weapons is bad. I feel like arcane damage is unnecessary, Bolt seems to excel against most enemies, Fire does against beasts.
Basically there's no reason to go Arcane or pump points into it. You're better off using flame paper or bolt paper for the bosses that have certain weaknesses.