"All of creation cares not whether you live or die."
Rusanov's Axe is a unique weapon that can be obtained by purchasing the Collectors Edition of Darksiders II. It also is a unique drop from the third soul fight in the lair of the Judicator. However, it is possible to get a free code for Rusanov's Axe from the Darksiders II page on Facebook, simply by "liking" the page. You can also get it on PSN Store for .99 USD
Obtained after defeating the Bone Keeper and the Bone Giant in the Judicator's Tomb. Indeed and in Deathinitive edition only, this axe becomes a possessed weapon which Death can increase in base power and add new abilities to the weapon.
"Brought into countless battles by a once great demon lord. The face of the axe displays of those it has slain. Said to consume the soul of its victims and writhe them in eternal agony."
It is also known to be a possessed weapon as well.