So long as a card was printed at common at any point, it is legal in the format (excluding acorn-stamped, illegal, and banned cards)
Yes, Garth One-Eye is a key card in 8 combo(s) in our combo database, linked from the Combos section of this page.
If you can find them at MSRP, snap them up, but you should be prepared to pay a fair amount for each
Aujik Spatial Bodies (2016) Spatial Bodies depicts the urban landscape and architectural bodies as an autonomous living and self replicating organism
Many mechanics have changed, rules have been restructured, and cards have been rewritten and re-released several times over
Remarkably, these cards continue to see play in modern Yellow decks