Red Death dropped for me the other day and I must say this gun is pretty good against Vex and Cabal.
Not my cup of tea in the Crucible though, much rather a Shotgun or an Auto Rifle.
For crucible, you really need 2 consider 2 things and 2 things only:
1. Your personal class talents, like for instance, for my guy a titan defender, the ward of dawn passives, one grants extra weapon power or armor when passing through, its good in either pve or pvp, but honestly, one that is worthless in pve is when you get absolute armor but only in the ward, this is useful in pvp. Another deal is, when the ward is fired upon there is a passive that lets it generate orbs of light, this is useful in pve, but worthless in pvp because while the effect will still work, most will know that the ward cannot be broken unless the caster is killed, otherwise the thing needs to go away on its own, likewise, its also because you know they wont waste ammo, so for my case in this, I chose armor of light and the passive to make my melee barrier last longer and have more power. Another deal is grenades as well, magnetic can net me a few kills since it sticks and blows up twice, spike is worthless in pvp due to the small blast radius and fact people are always moving. So instead I use suppressor grenade, it blows only once but if anyone is caught in it, they cannot do anything but run and gun, this means they cannot use their melee special, jump, super, or any other passives while the effect is up. This is my favorite because it leaves people defenseless and its incredible. This is a small example of one thing. The other is, you need to basically figure out which melee, jump, and stat distribution works for you, more armor, speed, or recovery, any class can obtain any max, but you always have 50% of your classes prime stat, for me as a titan, this means I can always settle for a normal armor rating with higher speed and recovery.
2. You need to make sure you use weapons and armor that actually work. I mean not by the attack or defense ratings, for the sake of balance, all weapons are given the same power in their class, for instance an auto rifle with a smaller mag like at 34 will be the same in power for an auto rifle with one around 28, but those with around 50 or more will be weaker. Generally, all melee, grenade, and special cooldown effects from armor don't influence as much, strength, disipline, and intellect stats are generally scaled back in this mode for the sake of balance, though personal talents still make a difference. But for anything, dont get rid of a weapon just because of its quality, if it has good abilities, it can be a good pvp weapon if its no longer worth something in pve, the attack power makes no difference, only the ratings on its stats like impact, rate of fire, reload, etc make a difference. I myself have a blue auto rifle, its powerful, its level 20, yet its very standard and it works and its helped me against even those with epics and exotics. Its standard cause well, it has about 30 rounds, good accuracy, moderate power, great stability, little recoil, it has some effects like it gets more accurate the longer it is fired and it has increased stability as a passive.
Yet you need to be careful of some abilities, some weapons, outright suck, depending on what the game gives you, you need to check abilities and make sure they are something practical, make sure they are actually good, like what i said, my rifle had a passive that made it more accurate the longer it is fired right? Well some heavy machine guns will have this too, but they may also have little to no stabiity and high rates of fire, this is a terrible combination and just a weapon that should be scrapped. Its a complete joke, the point is, you need weapons that can actually function. What may be good for one weapon can be horse kitten on another, and some are just painfully terrible weapons designed only to be extra glimmer and weapon parts. Special mention (with fusion rifles, elements don't matter, go to town with whatever has a good charge rate you feel, only downside to fusion rifles, they cannot get headshots)
Some passives that are ideal you may seek are:
-increased reload speed
-chance of increased damage on reload
-increased accuracy as its fired (if the gun itself is accurate already)
-faster/near instant reload when clip is empty (this is amazing on an accurate heavy machine gun, I have one with a blue rarity, even some one shot clip weapons hold this, if you get lucky you may fired a rocket launcher with this stuff!)
-quicker draw speed
-reduces grenade cooldown/super cooldown on kill
-explosive rounds (on handguns and snipers a lot)
-holding extra ammo (sometimes bundled in with another passive)
-ammo regeneration (this is on an exotic shotgun i hold)
-shooting any ammo to get it back for that weapon
-gun has increased hip fire accuracy
-the bottom half of the magazine can cause more damage
-move faster while aiming this weapon
Some that are moderate would be:
-clown magazine granting larger than normal clip size
-one round in the magazine does more damage
-a precision kill gives more accuracy
-a precision kill gives you more damage
-reload faster with a specific weapon
-gun rounds can ricochet
-rocket rounds can seek targets
-rounds have a chance of over penetration nailing multiple targets (generally a default ability in all snipers though its not listed)
some to avoid are:
-taking fire while aiming this weapon makes it easier to aim (just stop here, just stop, the point of the game is to not die, so naturally, anything requiring you to take damage when fighting beats the purpose of this, just destory any weapon with this ASAP, its a waste, if you want to use it in pvp, you will die.
-gun has a chance to return ammo to a clip if it misses, (you always have primary ammo you can pick up from enemies and special weapon crates are around plenty.
-any sight that removes stats upon the weapons (take anything that you feel is good, but not too obstructive nor impactful upon the weapon stats.
-gun increases fire rate as it is fired (again a pointless one, don't get anything that goes full auto, generally you will find better weapons that grant this in a form anyways)
-increases accuracy when its fired yet the gun is very inaccurate (again, even on something like a heavy machine gun, don't use this, its a waste of heavy ammo and heavy ammo is fought over in the pvp matches, the point is to get kills with it, not waste it)
-has a chance of any of the above abilities from ideal or moderate (if you ever get this, the game is basically screwing with you, don't get anything with a chance of an ability another weapon can have occur all the time)
thats generally an outline, also take special note:
Anything i listed that could do more damage is not going to work in default modes, only buffs like from a defender or sunsinger will grant more damage, but in the iron banner these will work and likewise, the iron banner is where all your equipment matters. So an old not as good pve weapon can work in the normal cruicble, but not the iron banner.
Just try to find a setup with your talents and weapons and you will be fine, but think practically, think about it logically, there are guides out there so just think and find a playstyle that suits you.