The arc numbers are my favourite, especially how he seems to throw them in as much as he can and it always works.
Response to Cid:
I really think he's just poking fun with this whole... "Act 6 Intermission 5 Intermission 1". Though now we see how the Felt are being created, and Caliborn's Cal helmet. Man that thing is creepy.
I wonder what number 8 will look like...