This pair of boots roots your connection to your patron as an inseparable bond. This is to such an extent that your patron will potentially come to you aid.

Otherworldly Intervention: Whilst attuned to and wearing these boots you can use an action to call on your patron to intervene on you behalf when your need is great. Describe the assistance you seek, and roll percentile dice. If you roll a number equal to or lower than your warlock level, your patron intervenes. The DM chooses the nature of the intervention. If your patron intervenes, you can't use it again for 7 days. Otherwise you can use it again after you finish a long rest. At 20th level, your call for intervention succeeds automatically, no roll required.

Loyal Subject: Sworn loyalty to your patron deserves boons upon awakening these boots you can activate Misty Step that costs 10ft of movement instead of a spell slot, this can be used as long as you have at least 10ft of movement multiple times per round. You also gain the ability to cast Dimension Door as a Bonus Action as you wish. You can also channel the power of your patron to fly giving you a flight speed of 65ft.

Notes: Set: Innate Speed (Flying), Warlock