What type of chemical reaction is happening here? 8fe + s8 --> 8fes

This is a synthesis reaction since you are taking two elements and creating one (opposite of decomposition).  I think this might also classify as a redox reaction as well since it appears as if iron is being oxidized and sulfur is being reduced (iron is loosing electrons while sulfur is gaining electrons).

I hope this helps.  Let me know if anything is unclear.