The Archmage

Your patron is an archmage, a wizard of immensely high power, that decided to share a portion of their arcane potential with you. Archmages vary greatly in alignment and their goals: some are benevolent, and work towards protecting others from cosmic threats, such as Elminster. Others just seek knowledge and power for its own sake, like the Simbul. And finally, others search power for deranged and nefarious means, like Halaster Blackcloak and Acererak. Regardless, a warlock whose pact was forged with an archmage can expect to be thrown in a cosmic game of chess between creatures with unfathomable arcane powers.

Wizardly Magic

When your Spellcasting feature lets you learn or replace a warlock cantrip or a warlock spell of 1st level or higher, you can choose the new spell from the warlock spell list or the wizard spell list. You must otherwise obey all the restrictions for selecting the spell, and it becomes a warlock spell for you.

In addition you are able to attune to any magic item a wizard could attune to.

Archmage's Gift

Starting at 1st level, you gain a spellbook from your patron and are able prepare your warlock spells. You can change your list of prepared warlock spells when you finish a short rest using your spellbook, if you lose your spellbook you can perform a ritual that lasts one minute to replace your lost spellbook with a new one with all your previous prepared warlock spells in it or different spells, the previous spellbook is destroyed when performing this ritual.

Additionally, any spell that you have prepared in your spellbook that has the ritual tag can be cast as a ritual.

Spell Mastery

Starting at 1st level, three times per long rest you can cast warlock spells you know of fifth level or lower without expanding a spell slot.

Additionally you can cast any spell that has the casting time of an action as a bonus action instead.

Spellcasting Affinity

Starting at 6th level, your spells gain the ability to undercut resistances. After a you finish a short or long rest, you can choose one damage type. When a spell you cast deals damage of that type, it ignores resistances and treats immunities as resistances. This lasts until you choose another damage type using this feature.

Weave Mastery

Starting at 10th level, all creatures have disadvantage against saving throws of your spells.

Ward Of The Weave

Starting at 14th level, you are resistant to damage from all spells and magical effects.

Additionally you are unaffected by spell effects of any spell of fifth level or lower that would have you make a saving throw unless you choose to be affected by them.