You (poor Anon) are asked to judge a Primarch Body building competition. How would each of the primarchs bribe you in order to win?
Lion El'Jonson - He... wouldn't. lmao.
Fulgrim - You'd have no choice but to pick him. HOW CAN YOU NOT SEE PERFECTION STARING YOU IN THE FACE?! Would offer you any and everything your heart desires. Including him.
Perturabo - He'd bribe you with life (read: really-but-not-really give you the option between life and death) so long as you DON'T choose Dorn.
Jaghatai Khan - ...Isn't really interested but... wanna go fast?!
Leman Russ - He'd bribe you with... him. Wanna touch this fucking masterpiece?!
Rogal Dorn - Is also not interested and as such, doesn't bribe you. In fact, he doesn't know why he's even in this 'competition'. Turns out Alpharius signed him up because he's a messy bitch who lives for drama. Can hit those poses like a pro, though.
Konrad - He presents an offering. I'll leave that to your interpretation.
Sanguinius - Um... you can touch his wings?
Ferrus Manus - A nice weapon forged by yours truly.
Angron - He also bribes you with... not death. At least, that's what Khârn said. Huh. All Angron did was scream and grunt so what the fuck?
Roboute Guilliman - Bribes you with bigger tax returns. Baby, the way your life would be set up...
Mortarion - Does intense staring count as a bribe?
Magnus the Red - The way Magnus' ego is built, he's sure he'd win. So he bribes you by making the competition 'fair', not competing, and instead opts to help you judge... which pisses Leman off because he knows that bastard will try to cheat him.
Horus Lupercal - He is an icon. The moment. The Lupercal. He bribes you with a chance to ride on the shoulders of the Beloved Son himself. Or something like that. May or may not be a double-entendre but if it is... ( ͡° ͜ʖ ͡°)
Lorgar - He bribes you with a chance for salvation so long as you accept the Emperor of Mankind as your Lord and Savior.
Vulkan - Does he really need to bribe you, though?
Alpharius Omegon - Too busy fucking shit up behind the scenes so you're the one bribing him/them to fucking STOP.