Just tried out the modified Rain of Destruction talent for Gul’dan as per patch of 22 May 2019 and just wanted to give my feedback.
I like that it now can be cast and then you can continue with what you were doing, however due to the randomness of the meteors (as also stated in patch note) it still is far from a viable talent. In team fights where people are constantly moving it is more like a magnificent piece of firework rather than a source of damage. I guess it has its uses should you have no sieger on the team, however Gul’dan is very squishy and is very ill suited for the position as sieger.
Even though I like the idea of Rain of Destruction it might be a better idea just to delete the talent all together and replace with another iconic warlock/Gul’dan ability. I am thinking Chaos Bolt.
Until a better solution I will stick with horrify