User blog comment:Tailzdafox/Ark, The Rune Constructor/@comment-4087140-20121003190430/@comment-5574850-20121003194327

Just the same 5 seconds, because if you've just taken damage chances are that you're going to run away from that source of damage (or attack it). If 5 seconds seems too long it's because he also regens his HP faster while it's active, so having it less than that would possibly be a little OP.