Melee Caster.

As a spellcaster, you are naturally weak, but as your spell slots diminish, you get risky.  To counter this, you imbue a weapon with magic.  When you take this feat, you may choose one weapons to imbue with magic.  When you do this, you can use your spellcasting modifier instead of your strength or Dexterity to roll for hits.  Along with this you gain proficiency with just that weapon.