I'll use what Tom stated earlier as a jumping off point... Damage tests are given at the end of the turn in which the damage is received.
Healing Bashing: Free action, static against 7 physicals to heal one bashing, once per turn.
Heal Lethal: Take an action, static against 7 physicals to heal one lethal.
Athro: You may chop once for every lethal at the end of the turn in which it was received. Success or ties reduces that damage to bashing. Failure means you may not test to reduce more damage that turn.
Elder: You may chop once for every agg at the end of the turn in which it was received. Success or ties reduces that damage to lethal. Failure means you may not test to reduce more damage that turn.
Combat Healing Gift: No chop is needed, once the Gift is activated (for one scene or one hour). When the Gift is active, one level of any damage may be healed each round as a free action.
Aegis Shield (Ahroun, Advanced): In RAtC, the advantage of this Gift over the Athro (and Elder) Rank Bonus of testing-down Lethal Damage to Bashing Damage, is that through use of the Gift, there is no test and Lethal Damage automatically becomes Bashing at the time the damage is taken.
As far as Aegis Shield is concerned, it doesn't affect the Athro Rank Bonus of testing-down Lethal to Bashing, as no Athro would possess the Gift in the first place. The Gift simply makes the conversion of Lethal to Bashing free for the Elder, making what had formerly been the character's Athro rank benefit, entirely free. Of course, Aggravated damage would still need to be tested down to Lethal as normal for the Elder, though any resulting conversion to Lethal Damage would automatically become Bashing Damage with the Gift.
All of this, is why Elder Ahrouns are badass