Background of my answer:
One of my favorite books, Paladin of Souls by <PERSON>, had a scene where one character's injuries were being "passed off" to two other characters. The one "passing off injuries", a great warrior, was sent sneaking into the enemy army's camp. The two "injury receiving" characters were safe, laying in the castle, with attendants at hand to bind wounds as they occurred. I would describe it in more detail, but I would rather not spoil it, as it's a fairly epic part of a great book.
How it could be applied:
Using this as a model (including genders), I would expect combat to go like this:
Pre-battle:
* <PERSON> prepares for battle by doing some stretches, swinging his sword a few times, etc.
* <PERSON> prepares for battle by donning armor, retreating to the tower where attendants will have a good view of the battle. She will get strapped to a table or the floor, or maybe the armor is heavy enough to hold her down.
* <PERSON> heads out to battle. Not fearless, but knowing he will be well-defended. While he's out...
Case 1: <PERSON> gets hit with an attack that the armor can handle.
* For the <PERSON>, conservation-of-energy and conservation-of-momentum kick in. I would expect the armor to "feel" what it could from the impact, then have the rest of the momentum (and remaining energy) transfer back to the <PERSON>, i.e. he could be knocked down by a strong enough hit. Impacting on the ground would also be transferred partly to the armor, and then back to the warlock.
* The squire, in the meantime, is jostled as the armor she is wearing seems to be hit out of nowhere. Because she is tied down, it doesn't do a whole lot, otherwise.
Case 2: <PERSON> gets hit with an attack that damages the armor some.
* <PERSON> says "ow", among other things. If he has been hurt, I imagine him to either retreat or keep fighting in an epic way. 627
If he has not been hurt, he will try to avoid being hit in the same spot, knowing he has a weakness there.
* <PERSON> and attendants notice the armor get damaged. <PERSON> is probably a bit shaken, but otherwise still unharmed. If the armor looks repairable, the attendants get to work right away, forming new material onto the armor to cover/reinforce the hole/break.
* An extension of this idea: If the armor was optimized to be swapped out in segments, the attendants might watch for a moment when the warlock is safe, then swap a damaged segment of armor out for a new piece, pit-crew style. This would be another reason the warlock would try to not be hit in the same place - he might have a moment of no armor, with knowledge that more armor was on the way.
Case 3: Warlock gets hit with an attack the damages the armor a lot. (Like, somewhat crushed, or maybe cleaved)
* The squire very likely would be injured by the deformation of the armor. If she's still alive, she probably says "ow", and she and the attendants will get her into new armor as quickly as possible, assuming it's safe for the warlock. If she's not alive, the attendants will either put her in new armor (on the off-chance she's actually just unconscious) or carefully remove her body from the twisted wreckage and begin preparing her for funeral rites, knowing they've done their best to help the warlock.
* The <PERSON> will definitely say "ow", if he's not dead from the blow. A crushing blow would impact hard, a cleaving blow would probably cleave him, too. This isn't to say he can't have awesome "block it with his arm" moments, but a heavy-duty mace or axe (or siege weapon) might make him hesitate.
* If the <PERSON>'s not dead, he'll be checking himself for armor as an indicator of his squire's life. Whether or not she's alive, he'll be retreating hastily - either because he now has no armor, or because the squire needs a chance to swap armor.
Odd circumstance: <PERSON> dies, squire does not. (e.g. stabbed with a <PERSON> dagger)
* If the <PERSON> dies and the Squire does not, what happens is dependent on the nature of the spell.
* If the magic persists after the warlock's life ends, the squire and attendants may not even know he's dead unless they see him. 516