Don't mind Wah he's insane
just kiddin'
If you do all th questes you should be able to have Power Word Kill
I came to 7th level spells
in chap. 2
so

Im in the sewers under the temple district and a mage named Mekrath has asked me to get a mirror from a devil that is in the sewers. I suppose its the devil surrounded by kobolds in the center of the map, but i didnt get any mirror from him. Have i done something wrong or its simply that i must follow the game and it´ll appear ??

THANX

That guy in the middle is not the devil
I think
Don't know where it is

No he isn't...that's a rakhshasa man!
The imp is in the southeast corner of the map, he's got an earth elemental with him

Yeah that
I knew that
Just ehm
Forgot

You can also ignore Mekrath's little task and kill him, instead.

that's exactly what I did!!! cheeky fool - who did he think he was, ordering a Holy Mage about?

Casted power word kill and didn't even raise an eyebrow!!

Well, I got the mirror...and killed him. He offered me a slave as a payment !! Slaves to me!! He should had cast know alignment on my good sorceror before offering me such things !!

Wah, who did you get power word kill so early in the game, or you
are you chapter 6 while doing this quest?

Not a chance, Power Word Kill is a 9th level spell,
if you dont cheat you have to buy from Ribald or somebody else!