Board Thread:General Discussion/@comment-25814498-20150505201606/@comment-26328217-20170304154634

Name: Adaptation

Category: Specialization

Description: The user slowly becomes more and more resistant to any attack used against them; punches will do less and less damage, as would guns or even specific Nen attacks (for instance, the user would eventually become immune to Killua's lightning, though they'd still be vulnerable to Gon's Jajanken until they adapted to that as well).

Limitations: The adaptation is not instantaneous and takes multiplt hits (generally around 20-30) to fully block some sort of attack. Additionally, new attacks will deal a lot of damage until the adaptation sets in. Finally, there is a time limit on how long these adaptations last - 24 hours after the last attack. So a user can become completely immune to punches, but 24 hours after the last punch to hit them, they'd be able to be punched again and have to re-adapt.