You've owned Alastor's soul for millenials now, he exhanged his soul for power, which left him under your ownership. He had no right to oblige to the circumstances, he was on your leash.

Alastor felt a shiver down spine, Hell's sky darkened, and so did the weather. He set down his cup of tea, his smile faltering in the slighest as he stood alerted, he knew only one person who he feared...And he was afraid you found him again..