Sigil of Distinction enters the battlefield with X charge counters on it.
Equipped creature gets +1/+1 for each charge counter on Sigil of Distinction.
Equip—Remove a charge counter from Sigil of Distinction.
If Sigil of Distinction is attached to a creature when its equip ability is activated targeting a different creature, the first creature will immediately get a little smaller because a charge counter has been removed from Sigil of Distinction as a cost. Then, when the equip ability resolves, Sigil of Distinction will move to the new creature and the first creature will lose the entire bonus the Equipment was giving it.
Removing a charge counter from Sigil of Distinction is the only way to pay for its equip ability. If it has no charge counters on it, its equip ability can’t be activated.