Even if you don't care about the defender-specific design here, a legendary artifact that passively draws cards and spits out blockers might be worth a look in some decks
Mind's Eye If we go purely by card-drawing efficiency, Mind's Eye is one of the greatest artifacts for Commander, letting you draw at the very least three extra cards per turn as long as you have available mana
A couple of months ago we wrote a deep dive article into Who Took The Trident that covered much of the story so far
C Common Realm Elegy X SPELL Add 1 "Veda" monster from your Deck to your hand
Shadowheart, Dark Justiciar I love sacrifice outlets because sometimes people get grabby with our creatures
Secondly, keep in mind that 'lag' is a general term and could apply to both slow down (e.g., frames per second/FPS), or reduced responsiveness during gameplay