On the contrary end times khaine is a huge improvement for my army (with the cast rules in the upcoming 2.6k tournament ie successfully cast means meeting the casting value)
I've written a list for that and I take a level 4 vampire lord with lore of Vampires. In the army is a Mortis Engine, a heirotitan and a Casket of Souls for rare. This means I'm rolling 2 dice for the 12 + invocation and adding +4 for level +1 for book of asur +2 for Mortis Engine + d3 for Hierotitan and +d3 for dark acolyte.
So I'm adding between 9 and 13 to my magic total each cast and I don't care how well you roll for dispel your gonna run out of dice very quickly if I'm spamming that.
Even if I get u lucky and roll 1 for how many dice I can roll I still ok by need a 3+ to get the spell off!
With an average of 17 dice a phase that's a couple of three dice summons and 6 invocations a turn! Those zombie units will be in the hundreds in two good turns.
The Chaos against Humanity tournament actually rules that if the spell is dispelled, the same Wizard cannot cast that spell again, although a different Wizard my attempt it if all previous attempts have reached the casting value.
The spamming you are talking about isn't possible if someone dispels your first attempt.
"Let Ye be Warned"
"From Ostermark; your Doom shall be sealed"