Boomerang Betty - Spectral Throw for the New Leagues

This is a Scion build... (or Marauder - explained later)
... Meaning you will need to have at least completed Normal difficulty in one league. The reason I chose Scion is because she acquires the necessary skill gems through quests so we can avoid trading for them. The Scion also has the best access to early % life regeneration and % max life on the skill tree.

This is an Iron Reflexes build...
... Because of this, we will focus on acquiring Strength/Dexterity equipment. This will have a combination of Armour and Evasion, but all Evasion will be converted to Armour. We will primarily use Red and Green gems, which is easily available on this equipment.
http://pathofexile.gamepedia.com/Iron_Reflexes

This is an Unwavering Stance build...
... Meaning we cannot evade attacks. We have no Evasion rating since it is all converted to Armour, so this only gets rid of the default 5% chance to evade. In return we cannot be stunned.
http://pathofexile.gamepedia.com/Unwavering_Stance

This is a Resolute Technique build...
... We cannot crit, but we cannot miss. We get to ignore two otherwise vital stats - accuracy and critical hit chance/damage. This makes gearing easier.
http://pathofexile.gamepedia.com/Resolute_Technique

This is an Iron Grip build...
.. Our physical projectile attacks now increase in damage according to our strength. We should reach around 500 strength, or 100% increased physical projectile damage.
http://pathofexile.gamepedia.com/Iron_Grip

Put all that together and you get Boomerang Betty, the Spectral Throw Scion!