Where Grist really becomes overpowered is when used in combination with cards like Forever Young, which lets you put any number of creatures from the top of your deck into your graveyard
As you can imagine, blocking creatures with first strike is very difficult unless you have a creature that either has first strike itself or has enough power to tank the damage
VOJA VS JETMIR Another deck in the same colors, that utilizes the same strategy of deploying mana dorks, is Jetmir
Chandra, Fire of Kaladesh / Chandra, Roaring Flame Ive always liked the flipwalkers as commanders, since they let you use some of Magics main characters who usually cant go in the command zone
Creepiness aside, he seems like a cool recursive attacker who will continue to harass your opponents using the Armour of Shrieking Souls as long as you can make sure that their creatures keep leaving the battlefield