In general dimensional bolt is best when your enemies don't have any significant resistances, and there's no chance it will set off some chain reaction that will hurt your allies.
But I could see dimensional bolt getting a slight damage buff. If something is unreliable, something else needs to compensate for that randomness. To extent the fact that you can potentially access every surface through that one ability helps that, but the low damage for its AP cost makes its versatility fairly costly. Generally you'll be better off spending that AP any other way, unless you DESPERATELY need to bank on stunning an enemy and have no other options to do that, but that's more bad preparedness than anything.
I don't feel like the basic attack the summoner starts with should feel like an "emergency button." It's a fun ability, so its too bad it's mediocre. As far as scaling with intelligence, I'll say I like how summoner overall doesn't really depend on intelligence, but I'm not if any other stat would make sense to scale dimensional bolt with. It could scale with the summoning ability if you could argue it counts as "summoning" an attack from another dimension, but that's quite a stretch.
Last edited by Baardvark; 21/04/17 02:14 AM.