Não.

Maldições Imperdoáveis precisam ser lançadas com o desejo de causar dor, controlar, matar, como vemos em OOTP:

“Never used an Unforgivable Curse before, have you, boy?” she yelled. She had abandoned her baby voice now. “You need to mean them, Potter! You need to really want to cause pain — to enjoy it — righteous anger won’t hurt me for long — I’ll show you how it is done, shall I? I’ll give you a lesson —”

_{-Harry Potter and the Order of Phoenix, chapter 36}

Se você estiver usando a intenção de bloquear, provavelmente não funcionará.

Isto é adicional ao fato de que seria quase impossível acertar a mágica de propósito ...

Os feitiços provavelmente ricochetariam após o precedente.

Feitiços acertando em cheio tendem a ricochetear

Jets of light shot from both wands, hit each other in midair, and ricocheted off at angles — Harry’s hit Goyle in the face, and Malfoy’s hit Hermione.

mas que tal um feitiço ricocheteando Avada Kedavra você pergunta?

yelled his best hope to the heavens, pointing Draco’s wand:

‘Avada Kedavra!’

‘Expelliarmus!’

The bang was like a cannon-blast and the golden flames that erupted between them, at the dead centre of the circle they had been treading, marked the point where the spells collided. Harry saw Voldemort’s green jet meet his own spell, saw the Elder Wand fly high, dark against the sunrise, spinning across the enchanted ceiling like the head of Nagini, spinning through the air towards the master it would not kill, who had come to take full possession of it at last. And Harry, with the unerring skill of the Seeker, caught the wand in his free hand as Voldemort fell back- wards, arms splayed, the slit pupils of the scarlet eyes rolling upwards. Tom Riddle hit the floor with a mundane finality, his body feeble and shrunken, the white hands empty, the snake-like face vacant and unknowing. Voldemort was dead, killed by his own rebounding curse, and Harry stood with two wands in his hand, staring down at his enemy’s shell.

e novamente

“I miscalculated, my friends, I admit it. My curse was deflected by the woman’s foolish sacrifice, and it rebounded upon myself. Aaah . . . pain beyond pain, my friends; nothing could have pre- pared me for it.

Avada Kedavra tem precedente de ser capaz de ser richocheted.

Apenas se ambas as varinhas compartilharem o mesmo núcleo

When a duel occurred between wizards with wand cores harvested from the same creature, simultaneous spell-casting by both parties would trigger a rare, powerful effect called Priori Incantatem.

Se ambas as varinhas compartilham o mesmo núcleo, então dois magos lançando Avada Kedavra ao mesmo tempo induzirão Priori Incantatem e trancarão os dois magos juntos até que a magia corra Claro.

Claro, se as duas varinhas não tivessem o mesmo núcleo e os dois magos (assumindo que ambos tinham a intenção de matar) lançassem Avada Kedavra ao mesmo tempo, isso simplesmente resultaria no mortes de ambos os magos.

Não

As únicas proteções conhecidas contra o avada kadavra são

• Evitar ser atingido ao se esquivar ou usar um objeto físico
• amor sacrificial, não se sabe se isso protege você do feitiço, ou apenas a pessoa que matou a parte sacrificada.
• Compartilhar um núcleo e forçá-lo a lutar pode resultar em imcantartum a priori.
• seu oponente usando uma varinha que deve sua alegação a você, permitindo que ela se recupere.