Death SS - Black Mass

 Death SS - Black Mass (1989)

The title song of this record contains a longer latin prayer, an invocation of Satan.

Satana, qui unus es dominus nobis
prodimus deum orbis terrarum
sanctos pinguemque feminam.
Tibi profundimus sanguinem nostrum liberarumque
subscribamus atrum voluminem mortis.
Et gratiam tibi agimus pro peccata nostra.
Stigma, quod nobis ipse impressisti, ostendimus.
Tibi confitemur peccata nostra
ut coniungas nos convivium ubertatis.
Nostrum cibum Belzeb consecra et vinculum
nigrae catenae solida.
Coniunge animas saltatione et commissatione
ad honorem tui, ut disiungat nos lux, Amen.  

Satan, you are the only lord for us

we produce the god of the world

and the fat woman

We pour for you our blood and that of our children,

let us sign the black contract of death.

We show the sign, which you have imprinted us by yourself. 

To you we confide our sins

so that you join us in the feast of fecundity.

.Connect the souls by dance and coalescence
for your glory, so that light leaves us, amen.

Although the grammar is quite good, still there are some words which I can't unterstand.
What is the sense of the accusative plural masculine "sanctos"?
How to use the second accusative object "convivium"?
Is "Belzeb" dative case?
What means "commisatio" - here used in ablative case "commissatione"? The word doesn't exist, but there is "commissio", ablative case "commissione"- coalescence.