A Virginia transgender substitute teacher was arrested for allegedly plotting a chilling “murder spree” at a local school — and bragging online about having a disturbing hit list. Hadyn Dollery, 19, was busted on school grounds Monday after posting threatening messages on Discord targeting John Champe High School in Stone Ridge, about 40 miles west of Washington, DC, according to the Loudoun County Sheriff’s Office and multiple outlets. Police said a tip on the department’s Safe2Talk app exposed the suspect’s sinister online posts. Hadyen Dollery, 19, was arrested Monday for allegedly plotting a chilling “murder spree” at a local school. Loudoun County Sheriff's Office The accused would-be attacker allegedly unleashed threats against family and friends on the messaging app, including disturbing talks of a mass killing at the school, according to a criminal complaint obtained by the Loudon Times-Mirror. The warped teen, of Chantilly, also claimed to have a “kill list,’ the complaint said.…