I was wondering if an enemy who attacks me with a melee attack takes damage from both Guardian Blades and Fire Shield, or just one of the two? Can either/both be combined with the errata-ed Infernal Wrath power? Thanks again.
I see no reason why you could not combine all three of these powers against an adjacent enemy. You would have to have triggered Guardian Blades and Fire Shield prior to the attacks, and they are both minor Daily powers. Infernal Wrath is an encounter power, so can only trigger once.
Also, bear in mind that the triggers for each power are slightly different - Infernal Wrath triggers when an enemy hits you, Fire Shield triggers when an enemy makes a melee attack roll against you, and Guardian Blades triggers when an adjacent enemy makes an attack roll. So, if an enemy adjacent to you made a ranged attack against an ally, you would only get to trigger Guardian Blades. If an enemy made a close blast attack against you from one square away (i.e. adjacent) and hit you, you could Infernal Wrath and Guardian Blades only. To get all three, and adjacent enemy would need to hit you with a melee attack.