Regards to restoring the sanity of Mardaneus: How many levels have you gone down in the pit?
Have you opened all four tombs in the big room three levels down where all the skeletons come out?
After you open all four tombs and kill all the skeletons the tomb on the left in the centre of the room is unlocked and leads down to the last level.
You'll meet the necromancer that possessed Mardaneus, when he dies tons of skeletons will come out. You can either fight some of them or run out of the room towards the exit, then Mardaneus will appear and thank you than you will be taken to the surface.
Quest complete!
"2) I have got my second teleporter stane also but while getting the stone i am not able to get throught the locked door which lies after the dead man"
Which dead man?
"3) when i enter the grave in the grave yard near the farmland the save button gets disabled how to activate that button"
Do you save via the main menu? if so try using CTRL+S hold them down for a few seconds then release, see if that helps.
"4) which is the best character to play with"
Well I'm currrently using the male warrior and I find he's one of the strongest characters in the game, it just depends how you want to play the game.
Try all of them <img src="/ubbthreads/images/graemlins/badsmile2.gif" alt="" />