Iron Blood Aspect can only be used by the Barbarian class. In Diablo 4, the strength of affixes are randomly generated within a range of values. This is shown in [parenthesis] in tooltip above.
With Diablo 4's runewords, sorcerers won't be the only class who can teleport across the screen. Barbarians won't be the only ones who can shout so loud their skin turns to iron. Stealth?