Intros:
With Ravenous Hunger-Satyricon (When
he says "At my signal unleash hell")
Slayer-Raining Blood
Dying Fetus - Scum(All that coughing and stuff)
Cryptopsy - Cold Hate,Worm Blood
Cryptopsy - ...And Then It Passes[(You hear that?) and the
opening riff]
Dying Fetus - Schematics
Nile - Unas,The Slayer Of The Gods (the riff with
the acoustic guitar,which thanks to Johnmansley I
can play !)

Closings:
Dying Fetus - Scum(Take that motherfuckers!)
Nile - Ruins(the whole song as a closing to the album)
Thorns - Interface To God
Dodheimsgard - Wrapped In Plastic(same as ruins)

well most of them aren't riffs but anyway

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