[0.913] Krax hero spell issue

The recruitable Kraxian hero, Kallus Hairto, has a strange, probably bugged spell called Obsession. It's a spell given by a trait, not a mastery. It claims to boost production in a city by 3+1 per death shard, but it is only castable in combat.

It seems to act like a buff spell, but I can't work out what it does.

Here is a link to a savegame with the hero recuited:

http://dl.dropbox.com/u/18688706/odd%20spell.EleSav