You also can change that diabolic into a demonic or some other tutor and play this in modern, if you wished :P

This things gets nasty with the indestructible knights, getting +1/+1 counters / buffs.
Maybe try an Immortal Servitude; it's along the lines of Obz' Aid, but can grab multiples, especially since you have 2 playsets of creatures with 3 cmc (making the Servitude 5 cmc like the Obz). 
Also, you would probably like Castigate, and Purge the Profane, which would also trigger Thune's Archie. Dump a Diabolic or two, or a Sign in Blood ;p