What weapon should I pick?
This most of the time depends on your playstyle, Right now it’s very useful to have magic as your main weapon and whatever you feel comfortable with as your second weapon. Sniper rifles are useful for killing bosses from afar when you have a line of sight on the flag and fast firing weapons like SMG and AK are useful for dealing quickly with a big mob of enemies on the point. Explosion weapons like the grenade launcher are also useful in this situtation.
Protecting the flag
The best way to protect the flag right now is to all group up on the flag and spam magic at all sides. This will later not be very useful against enemies who fire fast weapons, and bomb dude.
Healing grenades are very useful for healing yourself and getting rid of poison. One very useful trick is to throw a healing grenade right on the flag when defending it. You would help yourself and team mates with this.
Reviving players is very helpful. When you are dead you don’t earn any money at all which goes to waste. Reviving them allows them to still earn money that they can spend on chests and reviving other players. Don’t revive players right at the end of the round though, they wouldn’t be able to get enough money back in time.
Before you start mashing revive as soon as you die, look first if it’s smart to revive yourself. If it’s almost the end of the round and you see that your team mates are still alive and doing well, then you should hold off on reviving yourself.
Safe contesting points
Sometimes a flag is situated so that you can hide behind a wall or platform and still contest the point. You can use this to your advantage to stop the enemies from capturing the point while still being able to do something against them. The best weapon in this spot would be the grenade launcher.
If you’re good at quick math, make sure you only purchase chests if it leaves you with enough money to revive. The cost to revive can be seen at the bottom of your Vices (default keybind is c). This is just a rule of thumb, and you can adjust how you play to this rule based on your number of antacids, the current difficulty of the waves, and if your server has a ‘designated driver’ (someone who is intentionally saving their money for revives).