You will lose this fight when it comes to Affliction spec, 100%.
You are wrong for this spec, mainly because SBolt being a cast and direct damage completely goes against DoT spec’s nature, much the same as how the stupid ability Malefic Rapture actually is designed. The difference is MR has 0.5 legs to stand on since it actually has something to do with DoTs, whereas Shadow Bolt has nothing to do with DoTs. Malefic Grasp looked cooler graphic wise while fitting more thematically and the spec more appropriately.
Even then, it’s still ehh. Affliction’s never really had good animations, for the most part. I wouldn’t entirely figure they’d do it justice now. Drain Soul could use an HD version of itself, but again ehh.
No, it’s the most thematic filler Affliction could have outside of not having a filler at all and just being quite literally only about DoTs. That’s not possible, however, so as a filler it fits. It fits thematically as stated above, it fits with the whole mobility niche Affliction has because you can channel the spell for 0.5 seconds, move and still do damage during that .5 seconds due to partial ticks counting for Drain Soul channels.
We call that Demonology spec, except replace DoTs with imps/pets and replace MR spam with HoG and other things.
No, what I KNOW would look and feel awesome is having Affliction and other DoT specs actually being designed as being DoT specs, not some stupid nonsense of burst that is full on counter intuitive to the design direction of “damage over time” where time is the keyword here. Not some nonsense where they need a cooldown, they need soul shards, they need 15 stupid DoTs instead of just having 4 DoTs in total including their filler being a DoT. No, I don’t mean UA stacking, Drain Soul is a perfect filler for what it should be and does.
I don’t want to be casting anything besides Drain Soul when I’m playing Affliction, maybe Unstable Affliction and having my UA spell going back to Warlords of Draenor feeling where it’s an ultra mega powerful DoT that fits on each target, 1 per target and you can have as many of them out at once as you want.
What I KNOW would make DoT specs, like Affliction, feel much better is having execute DoTs back, too. There’s many other things, but again, just having DoT specs being true to the nature of their very existence instead of combatting against it would actually make the spec feel much better.
Shard spender, if I had to have 1 and if I had to have some kinda stupid burst, then Rapid Contagion 100% literally fits this description entirely and the thematics for Affliction. Going back to making Haunt the spender would also be decent, but even then that would still be “meh.”