Magnus is described in the various novels as being a giant, even among his fellow Primarchs, and the model certainly doesn't skimp on the size. I ended up having to mount him on a 60mm base, and he's almost 75mm to the tip of his axe! He makes even the massive Sekhmet Terminators look tiny.
I tired to give him a ruddy, reddish skin tone, which turned out all right. Originally I'd painted him up with white robes and red runic script, but they just looked terrible so I did a little repaint and swapped the colors for red robes and white scripts which ended up looking a little better. I also went with a nice big wolf pelt cloak to tweak the nose of our local Space Wolf player. All in all, it's not my favorite Primarch model that's out there, but it's what was available. He won't be part of the army I'm taking to England, but nevertheless it's good to get him done and out of the way!
The rules that I'm using for him are from the Age of the Emperor expansion pack available from the Tempus Fugitives site here:
The Primarch Magnus the Red, the Crimson King
Upgraded Unit Type: Heavy Infantry
• Primarch Armour (The armour provides a 1+ armour save [remembering that a roll of a 1 is always a failure], the Relentless special rule and a 4+ Invulnerable save.)
• The Red Staff (Master crafted force weapon)
• Psychic Hood
Ever Onwards! Magnus can never capture or contest an objective. For him the road to victory rolls ever onwards.
Titanic Might: Such is the power of the Primarch Magnus that he may re-roll all failed rolls to wound with close combat and shooting attacks.
Loss of Control: Should Magnus be slain, a psychic shockwave pulses from the fallen Primarch and his body is magically transported away from the battlefield. The effect on his army is devastating. All Psykers on the battlefield (friend and foe) suffer Perils of the Warp. Beware: The flesh-change affects the Thousand Sons as normal.
• Independent Character
• Eternal Warrior
• Master Psyker (C:SM pg 86)
• Gift of Prescience (C:SM pg 86).
• Surprise Attack (C:SM pg 85)
Psyker Mastery Level X: Knows all Thousand Sons and Librarian psychic powers. Automatically passes all psychic test and cannot be affected by devices that affect psychic powers.
Channel for the Warp: Magnus may cast up to four powers each turn. Each power may be used only once per turn, and only a single power may be used in the assault phase. Such is Magnus' capability that he can use more than one psychic shooting attack per turn; all of which must be directed to the same target.
Cyclops: Because Magnus has a single eye, his lack of depth perception means that even with his post-human abilities he has a Ballistic Skill of 4 and may not re-roll to hit with any shooting attacks.
So he's a beast on the table top, but is a massive liability to the army should he be slain. As it should be, I suppose!