Paragon of Fury is a warlord trait. The warlord gets S+1 every time he finishes a charge move, and because there is no timing restriction he can get S+5 when he finishes a charge move every turn ?
PARAGON OF FURY
After this WARLORD finishes a charge move:
Add 1 to this WARLORD’s Strength characteristic.
After this WARLORD finishes a charge move, roll one D6 for each enemy model that is within Engagement Range of it: on a 5+, that model’s unit suffers 1 mortal wound.