mtg manifest cards Dread (Card) Umbris gets +1/+1 for each card your opponents own in exile Manifest Token (2/2) by Peter

They do have some shadow creatures

Many combos utilizing these effects rely on them making 1-cost artifacts cost 0, particularly Sensei's Divining Top

Illustrated by Campbell White Standard Legal Alchemy Not Legal Pioneer Legal Historic Legal Modern Legal Brawl Legal Legacy Legal Comp

Many of the classic artifact combos are built from cards you could credibly play on their own merits, making it plausible to assemble them accidentally through the normal Go Wide gameplan instead of needing to tutor for them

The best strategy I've found against Tron is to just play an aggressive deck and have some Ghost Quarters

Investment: Some rare cards can increase in value over time