The Hallowed twin of Corruptible: get the Dryad's status check reporting a heavily Hallowed world - guides put the bar around half. Hardmode seeds the Hallow for you; accelerate with Hallowed Seeds from the Dryad, Holy Water, and the Clentaminator's blue solution. Rainbows everywhere, achievement in the post. A throwaway world spares your main one the redecoration.
