[Meglobob]

Shark attack is an effective spell to fight any underwater nation but against Rlyeh its especially good because the sharks are size 6. Thus all of Rlyehs mages will target there spells at them rather than your forces. The same with the mindblasts. I always cast this spell 1st combat round if at all possible when fighting Rlyeh underwater.

I have also had alot of success with golems with a bodyguard of mindless troops casting astral tempest.

If you are having a problem with magic duels, give your important leaders/scs/thugs items which give you a extra life. Then they after successfully magic duel you more than once.