Imperial planet in waaaay diffrent Galaxy

Ruthvocke noble family has been taking care of planet Solshomondona Reach, or in short Reach, for over 5000 years. Said family actually desrved being called noble, because they weren't ripping their people off, their PDF and Adeptus Arbites were one of best in entire Imperium and their Guard Regiments were very well equipped and trained. However them being so competent braught attention of one of bigger Chaos warbands. Planet defended themselves for over 12 years. But one of leaders of warband decided that if she couldn't have this planet then no one will. And sorceres aboard that fleet made a spell that was supposed to send Reach to Warp. However it did something very, very diffrent.