UnderscoreKillstreaks has received a full recode. Here's a brief changelog:

- Added commands to killstreaks
- Rewrote a lot of code
- Went open source
- Hooked to PAPI, now messages and commands have them supported
- New placeholders: %uks_player% and %uksmax_player%
- Keeping track of maximum killstreaks
- Killstreaks are now serialized
- You can switch between JSON, MySQL and MongoDB
- Command to forcefully serialize/deserialize streaks
- Uses ACF for commands
- Hologram leaderboards with DecentHolograms
- World blacklist
- Player blacklist
- Killstreak breakers
- Togglable reset on leave

Honestly, just read the documentation tab and the features list. The plugin has been recoded from scratch, so it's a better decision to refresh everything you've known about the plugin.

Fixed UpdateChecker (important)