Umbreon Gold Star (EX Power Keepers set) PSA 10: $70,000100,000
For example, if you control The Ozolith ("Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.") when Zack Fair's last ability resolves, you'll put the appropriate number of each kind of counter onto both The Ozolith and the target creature.
Enchantment Color tag templates(None) Binding the Old Gods (As this Saga enters and after your draw step, add a lore counter
Similarly to the other Swords of X and Y, this may lead to the Sword of Forge and Frontiers value increasing over time
However, this upside is only a reality for as long as you can continue to pay for it
The answer varies dramatically by era and card type