Start by searching here please:
https://www.amxmodx.org/compiler.php, for desired plugins.
Type in your keyword: boss. If that does not yield results; try another word. You might have to mix and match a combination of plugins to get what you wanted.
Warcraft mod has levels, unique special weapon powers per race / player type selected.
Until you said NPC I thought you meant,
https://half-life.fandom.com/wiki/Gene_Worm.
I have that guy appear in DeathMatches from time to time to spook campers instead of simply kick.
SF-Gun. Link please. Do not abbreviate. Google pulls up SanFran for SF. That is my entire point of taking interest here.
When I searched boss for you. Here is one. No NPC.
https://forums.alliedmods.net/showthread.php?p=186799
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