First, the creature tells the game it needs to die via state-based actions
This activation cost is relatively low, especially when paired with other walls that can add tons of mana based on your defender count
You want a creature to have double strike because you get the first strike damage and then another hit. Both keywords change the damage step, but double strike brings extra value and damage
Its not that hard to fix mana when Chromatic Lantern exists, plus all of the fixing in green
As an equipment, Chainsaw doesnt have the strongest impact on the game
With some minor upgrades, such as Snow White, Unexpected Houseguest and Nick WIlde, Wily Fox, this deck can quickly become a lot more viable