This includes cards in hand, cards in the graveyard, and exiled cards
It's great when the commander shares the creature type your deck cares about, and the mana bump it provides helps cast those over-priced Octopuses and Leviathans, which in turn get Arixmethes closer to waking up
Was also revealed the first two cards of the Final Fantasy Through the Ages Bonus Sheet (which will NOT be Standard-legal) reusing existing concept art on reskinned reprints from Magic
She goes hard with Spore Frog, Plaguecrafter, Secrets of the Dead, you name it
If you have more land than your opponent, or if your spells are cheaper than their counterspells, or if (as above) you have instants to lead with during their end step, it can pay to save threats in hand until they exceed the number of solutions your opponent can pay for, regardless of if they have them