Codex: Chaos Space Marines (2017), p40 — The Saint's Beacon

The shrine world of Nepthys Madrigal is the last bastion of resistance against the empyric incursion led by Lord Vileblight, a Greater Daemon of Nurgle. So holy is the ground and so valorous its Adepta Sororitas defenders that every outbreak of Vileblight's initial gambit, the Deathly Pox, is contained and sanctified within minutes of it occurring. In frustration, the Great Unclean One calls in an old debt with the Dark Apostle Kor Daradan. Within the month, the Word Bearers attack Nepthys Madrigal. As mortals, they are not repelled by the banishment sigils of the world, and cross the barriers that kept the Daemons out. They take the fight to the Sisters of Battle there with such vigour they force a full-scale evacuation of the populace. The conflict becomes a war of attrition in which the Chaos Space Marines prioritise casting down the temples and altars of the Imperial Creed, disrupting their wards. The planet falls to a wave of contagion and the subsequent Plaguebearer assault.