The Glaive has the Reach property, which increases its reach by 5 feet.
The Primeval Guardian ranger gets the Guardian Soul feature, which has the following effects (among others):
- Your size becomes Large, unless you were larger.
- Your reach increases by 5 feet.
The mystic can learn the Giant Growth psionic discipline, which has the following benefits:
Psychic Focus: While focused on this discipline, your reach increases by 5 feet.
Ogre Form (costs 2 psi points; duration of concentration, up to a minute) has the following benefits, among others: Your reach increases by 5 feet. If you're smaller than Large, you also become Large for the duration.
Does this image accurately depict the overall reach?
I'm not sure if this is how it works, nut it seems like a lot of fun to mess around with if it stacks like this. Even if you can only move 5 feet per turn, having a reach of 20 feet is interesting.