Try using another way to structure the sentence.
Fact 1:
Here is list of rules that aply on Vampires ...
Fact 2:
None of them aply to Astarion ...
Fact 3:
There is another rule, saying that Vampires are allways evil.
My claim:
Based on that they ignored so many other rules, i presume rule from Fact 3 is ignored aswell.
Your claim:
I presume rule from Fact 3 is followed.
My question:
Based on what?