You generally pray for people in purgatory don't you? Wouldn't people in Heaven have no need of prayer? They can talk with Christ himself!
Revelation is in the New Testament.
In Revelation 11, whether you take it literally or not, men breathe fire out of their mouths and kill people. That looks like violence to me.
And I agree with Classical_hero as well.
The soul is also alive in Purgatory, and since people who are in Heaven can talk to Christ himself why not ask for them to pray for you?