I don't believe the fight was that easy (became a 3 once, that's all)... Rangers are really overpowered.
For this fight, I decided to use bow + arrows of slay evil. Found a maze vault at 6300ft with Morgy outside. Read a few scrolls of holy prayer, and buffed the char with Resistance, Haste, Heroism, Berserker and Shield. See the screenshot below.
Morgoth:
summons special opponents (x3)
summons monsters (x3)
summons mighty undead opponents (x1)
hits you - you are severly crushed! (x1)
casts a mana bolt (x1)
Me:
used a stack of 12 arrows of slay evil (+6,+12)
used a stack of 38 arrows of slay evil (+15,+15)
used 23 out of 32 seeker arrows of slay evil (+18,+14)
used 4 potions of *healing*
Here's my gear for the final fight:
Chardump will follow as soon as I retire.