Feats

Feat - Iron-Grip
Requirements: Strength 20 or higher, proficiency in Martial and Simple Weapons, Level 8.

Your raw strength is overwhelming. You are able to use a weapon with the "Two-Handed" property in a single hand, as long as it does not have the "Reach" or "Loading" properties. You may not carry a Two-Handed weapon in both hands, nor can you carry a Two-Handed weapon in one hand and a smaller weapon in the other, though you may still use a shield.

Feat - Fast Casting
Requirements: Charisma, Intelligence, or Wisdom 20 or higher, the "Spellcasting" or "Warlock Spellcasting" features, Level 8.

Your skill with magic has grown to such an extent that you can perform the components for different spells at the same time. You may now ignore the normal rules for spellcasting limitations, meaning you may cast two spells of any level in the same turn, so long as one is an action, and the other is a bonus action, and neither have to be a cantrip.

You must have two free hands, or be carrying only your arcane focus in your hands in order to accomplish this.

Feat - Blind Fighting
Requirements: Proficiency in the Perception skill.

Extensive and continuous training in complete darkness or in some cases with the aid of blindfolds, have allowed you to hone your remaining senses to a razor's edge. This specialized combat training has granted you the ability to perceive your surroundings in ways others couldn't begin imagine.

You develop Blindsight up to a range of 20 feet.

Your Blindsight can only work in a setting where your character can use his other senses, like hearing and smell.

You gain advantage on Perception checks relying on hearing and scent.