The Counter Forces have immense power at their disposal. However, only the appropriate amount is unleashed to address a particular event. If the threat possesses an amount of power equal to X, then the Counter Force will deploy an amount of power just enough to snuff out X and eliminate the threat.
[1][4] The amount of power can be as small as nudging individuals into place through "coincidences", but it can also be as great as sinking an entire continent.
[4]
According to
Merlin in
Garden of Avalon, the Counter Force is a defensive mechanism born of the collective unconscious of mankind, and that the difference between the Heroic Spirits and the Counter Guardians of Counter Force is that the Heroic Spirits are summoned by the hopes of men, while Counter Guardians are summoned by the despair of men.
[7]