* Spell counters are a game mechanic: They are placed on permanents as a result of spells or abilities. They are not an action you take yourself.
* Actions are taken during your turn: You can only activate abilities, cast spells, and take actions during your own turn.
* Your opponent's turn is for them: During your opponent's turn, they are the ones taking actions.
Example: If you have a creature with a counter on it that gives it an ability that triggers on your opponent's turn, you can't *choose* to use that ability yourself. The ability triggers automatically when the condition is met.
In short: You can't manipulate spell counters directly. They are a consequence of game actions and can only be affected by abilities or spells that specifically interact with them.