I killed mad marten. He didn't drop anything and only worth 660,000 exp..

The reincarnation of Saxx!

He must be very important. I recruited him, portalled to a remote location and killed him. When i returned to Umpani base camp and looked at the automap a small red dot showed in the bar. Yes, a very annoyed Saxx, had to kill him again but i guess the Umpani didn't like it!

btw

If you want to kill NPC's for XP, kill don barlone. The Rakuza rattkin will seek you out in the roads (encountered them outside arnika) trying to extort some money. Simply say no and kill the mobsters. They come in groups of 8 - 10 lvl 10+ rattkin.

They also come if you don't kill Barlone.

Yeaaa...
BTW, does anyone know how to get those special items from NPCs?
I wanted to get that instrument Saxx was carrying. D'you think i'll get it if I kill him?

Go into his inventory.

Take the sax, and give it to another character (right-click on that characters portrait in the upper left corner of the inventory screen).

Take any item from the common invertory and give it to Saxx, to avoid the complaining. You can take it away again.