Не позволяем воскрешаться...

#include <amxmodx>
#include <amxmisc>

new player_dead[33]

public plugin_init()
{
    register_plugin("No Reconnect Player", "1.5", "Author")
}

public client_disconnect(id)
{
    if(!is_user_alive(id))
    {
        player_dead[id] = 1;
    }
}

public client_connect(id)
{
    if(is_user_connected(id) && player_dead[id] == 1)
    {
        user_kill(id)
    }
}