Here's my version of this plugin, I used it as a base so I need to give credit. (I also made it return plugin_handled so it doesnt keep saying command not found). I make it godmode everyone by default, and you type mortal (or say "!mortal") to turn it off for yourself.
!charge now only charges to 99% for the achievements that make you heal up to earn ubercharge (Placebo Effect).
Every kill is a revenge kill (thanks to chundo in the above posts).
Any bot will spawn 1 sec after kill, players spawn normal time. I had it spawn instantly but it got CRAZY they would spawn so fast, so 1 second works better.
I added these commands:
sm_nobluemeds - prevents people from being a blue medic. This is because on my server I have it blue team filled with blue bots. Also it coaxes people into the idea that RED team is where they should be anyway.
sm_bluemeds - turns off the above
I wrote up a forum post on my own forums about how to combine this with bots and other plugins to make a good achievement server.
here
I have not seen any other server copy the default godmode idea yet, I have to say it works really really well, better than I thought. I think thats a must for any public achievement server, even if you dont use my plugin, make everyone spawn with godmode, and have an easy command to turn it off (and print it to their screen at spawn), you will love it!