Only creatures with black in their casting cost or that are otherwise stated as being black, like creatures affected by Rise From the Grave, and creatures that have the artifact supertype can block a creature with fear
My tendency would be to lean on the Swords Sword of Fire and Ice, Sword of Light and Shadow, etc
Make sure youre the one playing it because youll otherwise end up hating it
It is, to put it lightly, ridiculously efficient
If they have a bunch of Celestial Colonnades, you can also keep some Fatal Pushes, or if that list becomes prominent the Bloodchiefs Thirst can become an Eliminate
What I didn't realize immediately about today's commander is that it was actually from a precon deck