I'm thinking only 2 of the 4 damage can be blocked in this manner. Any thoughts?

They are done separately, as they are different sources, so yes.

FI would block just ONE damage.

All damages are dealt separately (as Emperor's additional point of damages for example)

19 minutes ago, blackholexan said:

FI would block just ONE damage.

All damages are dealt separately (as Emperor's additional point of damages for example)

This is incorrect. All sources of damage deal damage separately, but for each source all damage is dealt together when dealing it to the same target.

1 hour ago, Willy Jarque said:

This is incorrect. All sources of damage deal damage separately, but for each source all damage is dealt together when dealing it to the same target.

I have been ruled otherwise but I see your point as potentially valid