ShadowCraft
This mod adds a craftable, upgradable, cloak that gives the wearer abilities theamed around darkness, as well as some more miscellaneous useful powers.
The cloak can have 3 different upgrades at the same time, from the following: Flight, Damaging blasts, Invisibility, Damage Reduction (possibly overpowered currently, I would like feedback!), and finally there is an upgrade to store more energy in the cloak itself to power its abilities. If anyone has suggestions for additional powers, I would be quite interested.
Additionally, the cloak allows you to teleport between Shadow Trees by right clicking on them. This sort of travel through the shadow dimensions is dangerous, and you will take damage based on the distance traveled. (Though never enough to kill you outright)
Each upgrade has 3 tiers (iron, diamond, and emerald), each successively more powerful.
(Try right clicking in the world with Congealed Shadows, you'll find it goes well with the Fog rune)