Arcane Intuition

You've honed your senses to the weave to such an extent that you can reverse engineer a spell by just seing it being cast. 

Ability Score Increase. Increase your Intelligence score by 1, up to a maximum of 20.

Eagle Eye. When you see another creature cast a wizard spell of a level you can use, you may attempt an arcana check with DC=10+the spell's level. On a success, you gain the ability to learn the spell for half price. You may attempt to learn a wizard spell that you have observed that is of a level you cannot yet cast. In such a case, the arcana check is made with disadvantage. When you reach a high enough level to learn the spell, you may do so at half price.

Decipher Spell-like Ability. With your dungeon master's permission, you may attempt to understand a spell-like or innate ability and transcribe it into a usable spell. All previous rules apply, but the dungeon master may adjust the DC as they see fit.