It's all a matter of technicality.

Technically they are two different people with two different personalities.

On the other hand they are technically only one person.

I have just created something that confuses even me. Is that bad? O_O

But the main thing is that it is not Tarquin who is dead. The dead person is Taroyn's brother. Tarquin is not the same person though in some ways very similar.