Although the Balrog has electicity immunnity, nullifyling Megatron's energy blast, his fusion cannon almost certainly breats through Balrrog's protections and damage reductions. ((I don't think they got Protection from Energy, Nuclear 30 in D&D))
Being a construct, Megatron is going to be immune to most of the Balrog's spells requiring will saves....and I see no evidence to suggest that the Balrog flames would be hugely effective.
I give the somewhat easy victory to Megatron.
Last edited by dergon darkhelm on Thu Mar 26, 2009 11:48 am, edited 1 time in total.