Warhammer: Purple sun of Xereus like it or loathe it?
The purple sun of xereus
The purple sun of xereus is a spell from the lore of death in warhammer fantasy battle. It is one of the few vortex spells and can with a single casting change the course of battles and decimate the enemy ranks, all whilst boosting the number of power dice you have at your disposal.
It creates a spinning ball of amethyst death (the size of the small template) that kills outright with no save of any kind any model that it touches that fails an initiative test. Being a spell from the lore of death it also receives the lore attribute life leeching, this grants you a extra power dice for every wound caused on a roll of 5+. Given the number of casualties it can inflict this can potentially increase you pool of power dice back to the maximum. To make matters worse it then hangs around moving randomly potentially causing more destruction in future magic phases.
There is also a higher casting version of the spell that increases the size of the vortex itself to the large template.
Some armies such as lizardmen, ogre kingdoms, orcs and goblins and dwarf's have inherently low initiative making the purple sun particularly lethal against them.
To make matters worse...
To make matters even worse is the default lore of shadow spell Melkoth's mystifying miasma, this low casting value spell allows you to lower the initiative of a unit by D3. As the best targets are already low initiative this can leave them at the low initiative of one, your not going to pass many tests with those odds.
Less likely but still possible (due to Azhag the Slaughterer or storm of magic) is the little waaagh spell itchy nuisance which lowers the targets initiative by D6.
The purple sun of xereus is also a vortex spell this means it can unlike direct damage and magic missile spells be aimed at units in combat.
There is a risk when casting purple sun of xereus when you roll the artillery dice for the distance that it travels you can get a misfire. This means the caster and any nearby models are likely to get hit and run the risk of amethyst based death and destruction. This of course is more deadly the lower the initiative of your wizard making it a risky casting for Lizardmen slann mage priests or Daemons of chaos Kairos Fateweaver.
The potential rewards however often overbalance the risk but bear in mind the deadly risk is still there.
A ray of light
There is one spell that offers protection from the dreaded purple sun of xereus from the lore of light. The spell speed of light grants the target both weapon skill and initiative 10 making the effected unit(s) much more likely to survive the ball of amethyst death. It can also be cast to affect units within a small area.
The downside is of course not every army has easy access (or any access) to the lore of light putting this ray of salvation of out reach for some armies.
Evens the odds?
A lot of powerful monsters and monsterous infantry are as you would expect of such lumbering brutes slow and therefore have a low intiative. Some people argue that the purple sun of xereus gives lower strength armies that lack warmachines and the like (most elf armies for example) a fighting chance against these foes.