What's the EULA on those assets? Are they UE4-only?
Q: How much do I have pay for the Paragon assets?
A: Nothing! They’re completely free. You can use them in both commercial and non-commercial Unreal Engine 4 projects.
Q: Are there any restrictions on the use of the Paragon assets?
A: As with all of Epic’s internally developed assets, the Paragon assets are only licensed for use in Unreal Engine 4.