I have a very specific question about the relations between a player that has bought some content and a free user.

I'm starting a campaign (Me being DM and a free user) using basic rules and free DnD Beyond content. My friend wants to play a Leonin (Race from Mythic Odysseys of Theros). 

I'd like to know how this can be done, these are the options I came up with...are they possible:

1. My friend purchases Mythic Odysseys of Theros book OR the race of Leonin itself...he creates his character and he joins my campaign (even though it doesn't uses the Mythic Odysseys of Theros content)

2. I purchase the book or the race of Leonin and my friend can then make his character since he is in my campaign. (Although I feel like this might be only possible with the Master subscription)

3. I purchase the book or the race and I will have manage his character since the paid content is on my account...not his.

Thank you for answer.

Option 1 will work if he is a free user. It's his content and he can use it anywhere. 

Option 2 only works if someone (can be any person) in the campaign has a Master Tier subscription. 

Option 3....I guess if you made an "unassigned" character in your campaign and let him claim it that would work. I'm not sure. 

The Leonin race is only a few bucks, so it makes the most sense for him to just purchase it himself, in my opinion. 

Thank you, good sir. My question has been answered to the full. :)