Specialize

Specialize is a character-specific upgrade for Shana that can be offered from a chest that is dropped when an elite enemy is eliminated.
== Details ==
* Gives 3 copies of the next chosen perk (an Upgrade, a Synergy or a Tome).
* In Endless: Gives 2^{n+1} - 1 copies of the next chosen perk, where n is the number of Specialize upgrades picked in a row.