The VOIDRUNNER'S CODEX is LIVE! Explore new worlds, fight oppressive empires, fend off fearsome aliens, and wield deadly psionics with this comprehensive boxed set expansion for 5E and A5E!
I don't have my books handy, but in the case of the Fighter, the free attack granted is stated to be an Immediate Interrupt (Immediate Reaction? It's been a while), which you only get one of per round.
Warden's Fury is an Immediate Interrupt. That means, if you use it once, you cannot use it (or other immediate action) again until your next turn ends.