I don't believe much of the book of revelations, because a lot of it is questionable, if not flat out false. Therefore, I don't know about any seals. In The Qur'an, we're told that there will be one trumpet sounded and it will be sounded twice. First sounding, everything and everyone in the world will die. The mountains will be reduced to sand, the sky will be rolled up like a scroll and the heavens will be rent asunder. Second sounding, the dead rise from the graves for questioning. If I were you, I'd check the scriptures in chronological order, The Book of Enoch, The Psalms, The Torah, The Gospel, The Qur'an, then see what similarities there are and go on those. Since all but the last have been tampered with, I recommend going from Qur'an first, then The Book of Enoch and so forth, because The Book of Enoch is the second scariest revelation next to The Qur'an in my opinion.
"Die before you die."-Prophet Muhammad (Pbuh)