The Build is completely focused on mana regeneration.
While this build allows you to gank relatively early you can also keep laning and get your items faster.
Using Divine Scepter and LSA after is a great combo to pull down your enemies and nuke them.
Later you can buy Dagon if you need more attack power to score a fast kill and go away fast.
Always make sure you don't face multiple enemies as this build doesn't offer much health or armor and Lina is really fragile.