How have you built Blech?
How have you decided to build this guy? To be honest, nothing especially stuck out to me about him, but then I got the idea "Wouldn't it be funny if I put Agatha's Soul Cauldron in here since I'd have a board of +1/+1 counters?"
Cue me then digging through my collection for the weirdest cards I could use as ingredients for the soup when I find [[Asmodeus, the Archfiend]] and his" BBB: Draw SEVEN CARDS" and all of a sudden I'm transfixed on the idea.
So for my shell, I leaned into stuff that fills my yard that I can either recur or feed to Cauldron once it's out, enough ways to try and reliably FIND Cauldron, stuff that makes the right typal creature Tokens as the "body," and odd utility creatures for Cauldron as the "organs," all while trying to squeeze the other necessities in.
https://moxfield.com/decks/WXzpQwjeWkifGZrvIYgPww
This is where I ended up. It definitely won't be the strongest at the table, but I think it will at least still function if I never find Cauldron.
I'm interested to hear how you decided to build this guy, and if there's any other commanders you looked at and said "No, I'm going to build you wrong" and still had it work