God Mode
In-game you can press '~' and enter the following string after the 'Omen' 
prompt to get full invulnerability: 

mdkGobSetDamageFilter(mdkGetPlayerGob(),0) 

Looks like the programming language? Yeah - this is trick for the internal game 
scripting system. But please note that this code must be re-entered 
periodically because the game doesn't store previous mode while map block 
change (block changing can be determined if your HDD reads something heavy and 
the game slowdowns for a while, or just see what you now is not invlunerable 
and your health value is decreasing). Hopefully you do not have to re-enter 
this long code - you can just bring console ('~' key) and then press Up-arrow 
key to get previous command form history.