Your example is a good one but is of the present perfect simple, not continuous. He died 10 years ago. Since this time, he has not been alive but dead. He is still dead now. When the main verb is "to be", it is not possible to produce a correct present perfect continuous sentence. In most cases, "to be" is used to describe states, not activities (e.g. to be dead) and so simple tenses are required. Even when one wants to move a sentence like, "You are being silly" into the present perfect (e.g. you have been being silly for some time time now), this sounds awful because of "been being" and so this tense is avoided.

“He has been dead for 10 years” is correct. It’s the present perfect simple, but with a continuous meaning. This is because the verb is a state, not an action. We could use an action verb “the deceased has been resting in the cemetery for 10 years.” Being dead has no effect on the grammar, however there is a really short list of action verbs that a dead person is actually capable of doing in reality.

I dont know how to answer with grammar terminology like present perfect, but that sentence is gramatically correct. "He has been dead for 10years?" works because of 'been'

Present percect talks about a time period from THE PAST to NOW. In this case, this person died in THE PAST and is still dead NOW. That is matchcubg with the criteria for present percect by say "He has been dead for 10 years." However, if the situation has been changed into a tome period from THE EARLIER PAST to THE MORE RECENT PAST then it would be past perfect. For example, "When she found him last year, he had been dead for 9 years."

If he is still dead, then it is appropriate to use the present perfect. If he has been revived or resurrected and is now alive again, then it is not.