New member here, and I have been working on revising all of the major boss battles throughout the game. The Revised Bosses mod modifies all health and damage output stats for each major boss battle and any minions that may be involved in that particular battle. Bosses are much more challenging, where in cases that a battle may have taken five minutes could now take up to thirty minutes. This mod has been tested and played through in Normal Mode only.
I had noticed some other folks posting about working on something similar but this particular mod only modifies health and damage output, where resist modifications were not done. Instructions for using this mod are provided in the Readme file included in the download below.
Direct download - (mediafire.com): http://www.mediafire.com/?tto4yam7o824bpf
For more info, updates and a YouTube example of the battle with Mikhail:http://lucidnine.wordpress.com/2012/09/24/revised-bosses-mod/