High Elf Battlemaster, no Warlock. Bump Int to 13 and pick up Ritual Caster (Wizard) with your level 6 feat. Cantrip of your choice, I like Message, Mage Hand, Mending, & Prestidigitation.

You get Darkvision & Proficiency in Perception to help your Non Bonus; and your Ritual choices are already better than a Tomelock dip.