This deck is super fun to play when it pops off.  I got the original list from Merchant's Aggro Walls deck (https://aetherhub.com/Deck/Public/10508.) I modified it to replace cards that don't exist anymore, then replaced Wall of Mist with Wall of Runes when War of the Spark came out because I think the scry ability can be really useful if you aren't getting the cards that you need (I probably will, at some point, change the sideboard to replace that Wall of Mist with something more useful as well.)  I also screwed with the lands a bit because I seemed to be running into a lot of situations where I was short a specific color of mana (usually white, if I remember correctly) to drop Arcades or High Alert.

Basically you drop every wall and then try to get Arcades and/or High Alert on the board so you can start going aggressive.  High Alert is actually a little better because then even Arcades gets a boost on his attack, and people seem to run way fewer enchantment removals than creature removals.

If you can get Tetsuko down then all of your walls are suddenly unblockable, and if you can drop Aegis of the Heavens on an unblocked/unblockable attacker you're going to murder that turn.

The Dive Downs come in clutch a lot of the time to protect Arcades or Tetsuko. making sure your threats are still threats for another turn.  Karn is just in there because a lot of walls are artifacts and so his Karnstructs can get a boost off that.

In the sideboard you have Shalai in case you want some flying and protection against direct burn/removal.  The extra couple of walls could probably be replaced by something more useful or synergistic with the deck.

The deck is a little slow, so you can't always get everything going, but when you do it's crazy fun.  The beefy walls are good at resisting aggro, and a lot of players will ignore them in early turns since they're just walls.  Amaranthine's indestructable can come into play in later turns to good effect.  Gleaming Barrier's treasures can help every once in a blue moon, but as I said earlier other players don't tend to try to kill your walls, so I wouldn't rely on them.  They could probably be easily replaced with something that has a more relevant effect.

It would be nice if this deck had more protection against flyers but when I made it Grappling Sundew was the only wall that existed with reach.  War of the Spark brought Wall of Vines but as a 0/3 I don't really think it has much value as a replacement for anything else in the deck (maybe I'm wrong about that.)