Eternal Witness (Topper) [Ultimate Masters Box Topper] XY25 then sacrifice it unless you

then sacrifice it unless you pay its upkeep cost for each age counter on it

Set: Alpha Edition Type: Creature — Wall Rarity: Uncommon Cost: {3}{W} Defender (This creature can't attack

Set: Dominaria Prerelease Promos Type: Legendary Artifact Rarity: Mythic Cost: {0} {T}: Add one mana of any color among legendary creatures and planeswalkers you control

Set: EX: Deoxys Type: Darkness Rarity: Holo Rare Retreat cost: 0

but how do we get down

Eternal Witness (Topper) [Ultimate Masters Box Topper] XY25 then sacrifice it unless youSet: Ultimate Masters Box Topper Type: Creature Human Shaman Rarity: Mythic Cost: {1}{G}{G} When Eternal Witness enters the battlefield, you may return target card from your graveyard to your hand.