If you are looking for Information about PSU Clementine, Go check their Wiki
Exact counterattack
From The re-PSUPedia
When you have a line shield equipped, depending on your evasive abilities you may be able to completely block an enemy attack. Immediately after you block, if you do a striking attack with the right timing, you can cancel the blocking animation and counterattack quickly. This is called an exact counterattack.
