Theres Tron and maybe other ways to ramp better to big Eldrazi, but that seems decent and its colorless
It's important to recognise that a lot of these cards only have value when applied well - for example, Dialga works because it supplies energy to other existing cards, but if they can't make use of that Steel type energy, then they're going to be useless to you
The idea here is that you would keep gaining more mana, and if you couldn't pay it, you would keep taking more damage
Heap Doll, Vessel of Endless Rest (sort of), Beckon Apparition, and the almighty Offalsnout are the only ways you can exile cards from your opponents graveyards, so the ding Spider Spawning got in speed and consistency is offset by the fact that you must race it and will struggle to ever gum up its engine
Clavileno is the best commander for the stock precon and the only one that actually cares about the Vampire part of Vampire Aristocrats