Beyond the vast horizon, beneath the sickening aura of the setting sun you spot it: the mobile fortress. Your guards sound the bells, but it is too late. The façade of the indomitable foe is overgrown in blossoms, glaring as bright as the silver moon - perhaps a result of its inconceivable speed. You gape as the fortress covers both the horizon and sky, and none of your creatures can stand their own against this amalgam of architecture.
Banded.
Trampling.
Vigilant.
Indestructible.
It is hopeless. Even if you survive, the vigilance of the bulwark renders any assault impossible. You could never hope to understand your loss; you do not even know what banding is.

...

That narrative is certainly hopeful, but with this deck, those dreams of crushing walls may finally come to fruition.

Strategy

Beat your opponent to death with walls. That is it. That is the strategy.
But how can walls attack? Well, with Assault Formation, of course. It also grants your walls the power needed to smite down your animate adversaries.
Banding is a neat mechanic too; do not let anyone tell you otherwise! Fortified Area is actually awesome.

Overgrown Battlement and Axebane Guard provide some of the best synergistic mana ramp in the game. Your Wall of Omens and Wall of Blossoms keep the construction coming!

If that was not enough, Vivien Reid is here to fetch out more walls and grant the perfect ultimate we could receive: he gives our walls +2/+2 vigilance (if not granted by Hold the Gates already), trample, and indestructible! With Wall of Glare in play, an creature-based opposition becomes trivial.

Notes on Banding

What is banding? It represents three effects:

1. After you declare attackers, any amount of creatures with banding plus up to one creature without banding that are all attacking the same player may be declared as a band. All banded creatures attack together and any block to any one of them blocks the entire band.
2. If a creature blocks at least one attacking creature with banding, the attacking player decides how the blocking creature assigns its combat damage.
3. If a creature attacks at least one blocking creature with banding, the defending player decides how the attacking creature assigns its combat damage.

Cool stuff you can do:

• If an attacking creature with trample is blocked by a banding creature, if the banding creature is dealt excess lethal damage, the banding creature's controller may decide NOT to apply trample damage.