This reference from Germany indicates that self-defense is lawful even if it ends the attacker's life, as long as the violence is not excessive for the situation.

https://se-legal.de/services/criminal-defense-lawyer/self-de...

They'll always rule that the violence was excessive. They'll say you could've slapped him in the face or disarmed the attacker.

The only ones getting a free pass are criminals. When they shoot and kill each other judges usually rule that it was self-defense. Ordinary people...no such luck.

Besides in Europe you always have to use physical violence to kill someone because firearms are illegal.