I agree. I just finished painting my Magnus so I did up a Battle report for him in the Chaos section, but yes eventually he was grounded.
There were times where it was touch and go, despite how the board looked. A few poorer 5+ rolls, and I'd have been in trouble.
To be fair, I am usually fairly lucky with my flyers. The idea, if he didn't land, was to either shooting him to death, or, grounding him.
I think for Grey Knights that's always an option but I'd ignore him otherwise. He's just too expensive and without a full Tzeentch Daemon fa m he starves the rest of the army of warp charges pretty badly. I thin this actually works to GK's advantage.
While we had to proxy today for the Thousand Sons, I tend to agree, but will eventually include him in my Thousand Sons for Fluff reasons. I'm thinking of avoiding the summoning spam.
I was lucky that I built many of my squads to include a Benesis awarding Stave. That Adamantium Will was a real life saver.
The most he managed to do was buff Nagnus in irrelevant ways due to the dice. Though one of his powers caused an interesting discussion. The one that lets him take control of an enemy unit. Know the one I mean?
I felt it shouldn't affect GKs, mainly because none have ever been corrupted. Though he passed the test for that one, Draigo denied it easily. Still, that was the most annoying thing he kept trying to do as I killed his summonses pretty quickly. Dragging with hammerhand is immense lol. (He was in a squad)
We played a maelstrom mission, he had Magnus (reserves), 2 exhulted sorcerors, 2x10-man Rubric squads with a Gatling cannon in each, a 5-man Scarab Occult Squad. He told me that came to 2K points.
He landed Magnus because he wanted to squash Draigo, which he did, but got swamped by terminators.
Out of the two Primarchs currently available, Guilliman looks to be the worst to try to take down for any of my 3 armies.