[Executor]

Utterdark is actually a horrible spell. Too expensive, too hard to cast and doesn't bring much to the table unless you're a blood nation (and everyone else isn't). BoT and Utterdark should switch places I feel.

As for dispel, it's a waste of gems.
You can never know how many gems a nation invested in a global so you'll most likely end up wasting a lot of gems even if you do dispel.
That especially goes for devastating globals like BoT and such.
For example, someone casts BoT with only 70 gems, so everybody contributes gems for dispel and it works, and than the next turn the same nation casts with 150 gems. At this either nobody has gems to dispel or they'll waste gems on small dispels.

So even when you think dispel is a good idea it's not.