User blog comment:AxisLight/Black Shield, Demon Attack!!!/@comment-4292163-20140126233634/@comment-1755882-20140127002325

It really doesn't matter what your Buddy is, but its best to select one that is Size 1 with no Call Cost. That way you'll be able to Call it under most situations. Also, one that's a staple for Magic World (like Buer) so you don't give away much about your deck right away. The last factor would be survivability, but nothing in Magic World really has much survivability.