The zombie woman gives the shield, but finishing the quest (after killing the devil fish and returning the woman to the lighthouse) gives the Call Colossus scroll. I do not think the quests rewards are randomized... Are they ???
For the wanderer scrolls, indeed it is in combat and it happens one times before finishing the 4 viking islands when delivering runwald (I had a flaming eye).
I know the Viking does not suck, it is just that I found it very less fun than skald or soothsayer. But indeed, I did not go far enough to have a clear idea. And as soon as I totally no loss with soothsayer, I may try a Viking
Not only Ahriman, it is the necromancer which is also tough... In my Viking game, Ahriman were beaten in 2 turns very easily without loss but the necromancer were way way too strong... Even with 3 call of nature scrolls...