(Updated to v14.17)
Nova has excellent point damage with her drones and her snipe ability. She can mark bosses to trigger them when Anvil scans an area, which saves Anvil from picking the Nuke mastery prematurely.
She has a hard time dealing with weak mobs, but in multi-player games, other heroes deal with small, weak and numerous mobs of enemies, not Nova.
Additionally, with the number of power cubes that spawn in the game, if picked up at proper times, allows Nova to deal with spine and roach drops with ease.
2 Possible Playstyles for Nova
Nova has 2 possible playstyles. The two playstyles are:
- Pure Snipe Nova
- Leadership-Drone Nova
A more detailed breakdown on Drones can be found here: https://cp2.fandom.com/wiki/Drone_Hangar_Mastery
Pure Snipe Nova is a much more efficient playstyle
The ELITE upgrades in V14.17 increase drone attack speed by +30%, drone acceleration towards the target and make drones shoot lasers at their target. On OS, Nova can reach her 25,000 score before the hour mark, usually at 55 minutes, but only with a lot of nuking. On HW, she can reach the same score slightly faster, but again, a lot of nukes are required.
Nova is much better off with a pure snipe build for 3 and 4-player OS and HW (the pros):
- There are no snipe resistant enemies in OS and HW
- Sniping with Executioner Mastery and Ghost Academy Training and fully upgraded Ricochet and Lightweight Equipment masteries deals far greater and more consistent damage compared to Leadership-Drone Nova. Additionally, Sniping has much larger range that Drone-attack range.
- Nova saves 2 masteries by not going for Leadership-Drones. She does not need to spend a Perk on Leadership, and thus picks Compartmentalization Perk, meaning she gets Lightweight Equipment for free. She also does not need to pick Combat Drones mastery. The 2 masteries saved means that Nova can invest 2 additional masteries in a Pure Snipe build, making her effective from early game onwards.
- Pure Snipe Nova avoids relying on Drone Wars talent, which is as good as a mastery. It greatly increases Drone attack speed, and sometimes Nova does not get this talent until levels 50+, making the whole Leadership-Drone build very weak. This is an unfixed game design issue that has existed for very long.
- Even with the ELITE upgrade, OS games are ending by the hour mark, making Pure Snipe Nova an even better playstyle that it already is for OS, because Nova can continuously snipe mobs of enemies to allow allies to focus on buildings instead.
- The same applies to HW games, where the ELITE upgrade does little for Nova aside proving melee firepower against Yagdras and Hives. The advantage of being an extremely powerful sniping force from the beginning of the game itself more than outweights this niche advantage of being effective against Yagdras and Hives with Leadership-Drones.
- Power cubes spawn frequently enough to allow Nova to melt surrounding roach and snipe drops with ease, further reducing the relative efficienty of Leadership-Drone Nova.
- The longer the game, the more likely there are inexperienced players. When deaths happen, there are punishment bosses. Pure Snipe Nova is extremely well suited to deal with them. This means that the longer the game goes by, the better Pure Snipe Nova becomes. Nova can and should also be continuously nuking after she picks Armageddon Mastery.
- A slight delay in reaching her 2500 with a pure snipe build. It is expected that Nova reaches her 2500 score by level 40, which is around the 22nd minute mark with a Leadership-Drone build. With a Pure Snipe build, Nova reaches her score only 2 or 3 minutes later.
- Leadership-Drone Nova is much better at handling Hives and Yagdras.
As such, the ELITE V14.17 upgrades does very little for Nova on Oldschool and Hellwalker. They might be effective in other difficulties where mechanics are different, such as the existence of snipe resistant enemies.
Nova's Perks for OS and HW
Nova has 3 fixed perks and the 4th perk is Compartment:
- (Hellwalker) Compartment
For quick entry of Perks at the beginning of the match, type (without quotes) "-perk owec".
- Onslaught adds +20% snipe damage and nuke damage and auto-attack damage, which makes it a critical perk for Nova
- Absorption is a core mastery for Sniping and synergizing with Killer Instinct mastery, by providing extra total energy for each stack of absorption.
- Weaponsmith allows Nova to outrange spore and hive detection range. It also increases drone damage, auto-attack damage, auto-attack range and snipe damage.
- Compartment saves Nova a mastery point when she needs to pick Lightweight Equipment.
NEVER pick toxic waste for Nova for Oldschool and Hellwalker multiplayer games. The only exception is for solo games. It might be fun to melt the huge waves of small enemies once the roach trap is triggered, but you are much better off saving your valuable perk for something useful. You will unlock your 2000 kill-streak bonus mastery anyways with or without toxic waste, meaning you are only trading off 1 perk for your 2000 killstreak mastery. Therefore, not only does Nova gain nothing (except slightly faster score unlock) in doing so, she also wastes 1 critical perk by picking toxic waste.
NEVER also pick Bug Zapper for Nova. While it is not a terrible perk, other perks are far more important.
NEVER replace Weaponsmith with Compartment perk on OS. Weaponsmith is a clear winner over compartmentalization, because when picked as a perk, weaponsmith is instantly completed for free. Compartmentalization needs to be picked manually, and takes both time and minerals to complete. Most importantly, Nova loses her attack damage, and attack range if she opts for Compartment over Weaponsmith.
Nova's Mastery Order for OS 
Pure snipe build on OS:
- Level 0 = Killer Instinct
- Level 10 = Lightweight Equipment
- Level 20 = Ghost Academy Training/ Ricochet
- Level 30 = Ricochet/ Ghost Academy Training
- Level 40 = Executioner
- Level 50 = Energy
- 2K Streak = Marksman
- Level 60 = Nuke
At level 20, Ghost Academy Training is a better mastery than Ricochet since it increases Nova's energy maximum (Remember that killer instinct procreates energy based on Nova's energy maximum) and reduced snipe cooldowns (combined with lightweight equipment and all talents) means instant snipes. However, if your allies are not donating minerals to allow you to reach 5000 minerals to select Ghost Academy Training, pick Ricochet instead.
By level 30, you should have enough for Ghost Academy Training in the event you could not pick it at level 20.
Once you pick Energy mastery by level 50, you will be a sniping force to be reckoned with.
For the 2K Streak, which almost always happens after level 50 for Nova, Marksman is the definite final mastery that completes full snipe Nova.
At level 60 and further, other situational masteries such as Nuke and Armageddon mastery could be useful.
Nova's Mastery Order for HW
Nova goes Pure Snipe:
- Level 0 = Killer Instinct + (Free) Lightweight Equipment
- Level 10 = Ricochet
- Level 20 = Ghost Academy Training
- Level 30 = Executioner/Energy
- Level 40 = Energy/Executioner
- Level 50 = Marksman
- 2K Streak = Global Nukes
- Level 60/ Free Hourly bonus = Armageddon
Pick Ricochet by level 10. Use Nova's Displace talent freely just for the sake of improving the ricochet step-wise upgrades. (and other step-wise upgrades as well). Ricochet will also accelerate your 2000 killstreak, which would happen imminently after level 50.
On HW, Nova completes her build by Level 50 with Marksman.
Comments on Nova's other Masteries
Marginal increase in snipe damage against armored targets. Armored targets include ultralisks and heavy flyers, which are slaughtered by a level 50 Nova with Executioner anyways. Marksman is always a better pick for Nova. However, Leadership-Drone Nova benefits non negligibly from Weakspot, since her Drones and Auto-attacks ignore armor.
Emergency Kit Mastery
The very last mastery Nova should pick. There is no reason to get placed in the line of fire. This mastery adds very little to Nova's capabilities.