Demon Prince with Mount?

[dhogan1]

So I was looking at Demon Prince and a conflict came up: So he can take any Chaos Reward and any Chaos Artefact. So my question is: If he take the appropriate mark can he also take that mark's mount? Like say he takes a Mark of Tzeentch could he also take a Disc of Tzeentch and become a Jetbike Monstrous Creature? Or Take the Mark of Khorne and a Juggernaut and become Calvary Monstrous Creature?

Very confused on what would happen with this/if it's even legal.

Thanks for any help!

[dhogan1]

Ahh nevermind. Saw footnote. Apparently only Chaos Lords and Sorcerer's can take it.

[Badtucker]

Also says they can only be used by infantry. Demonprinces are not infantry.