Demon's blessing

Demon's Blessing (2/day). You can use a bonus action to invoke the blessing of the demon for a minute, having your arms and shoulders (including any armor or clothes that cover them) being shrouded in darkness and growing black, demonic wings. You gain a fly speed of 30ft., are under the effects of the haste spell (requiring no concentration), but it isn't magical, and you ignore any levels of exhaustion you have while you are under the demon's blessing. Immediately after the blessing ends you gain 2 levels of exhaustion.