Path of Exile

Update 8/3/2020: A recent update apparently included a rework of the passive tree. While it shouldn't have any effect on this achievement, it did break the links I used when I posted this solution several years ago. I haven't played this game in quite a long time, but I believe I've managed to properly rebuild the trees with fresh links. Please let me know if you find any issues with them.

Keystones are the nodes on the tree with the big, fancy gold borders around them. They have huge effects on your character, usually both positive and negative. They don't work with just any build, so it's entirely possible you only have one or two. This gives us two options:

1) Save up points and spec into the closest keystones to your path on the tree, then use all the free respecs you've accumulated through side quests (or Orbs of Regret, though I personally think they would be wasted considering how easy the next option is).

2) Start a new character. Don't worry, you don't need to go far - if you play a Templar or a Witch, it will only take you 15 passive points to get 4 keystones. If you complete the Dweller of the Deep and Marooned Mariner side quests, you only need to reach level 14.

Templar:
https://www.pathofexile.com/fullscreen-passive-skill-tree/3....

Witch:
https://www.pathofexile.com/fullscreen-passive-skill-tree/3....