Dr. Siebren de Kuiper, perhaps better known as Overwatch Sigma, was once a renowned Belgian astrophysicist based in the Hague. As he furthered his studies into a way of safely harnessing the power of gravity and black holes, he ventured to a space station in order to test his hypotheses. Unfortunately, his endeavors were fruitless, and his exposure to misunderstood cosmic forces left him irreparably damaged. Upon his return to earth he was swiftly institutionalized, and remained under lock-and-key until the nefarious forces of Talon encountered hearsay about his newfound gravitic abilities and broke him out, in order to exploit his powers to further their criminal agenda in Overwatch.
The most recent addition to the hero roster, Overwatch Sigma is categorised as a tank, but is quite an unconventional one. He boasts the same bulky health pool and sluggish mobility of most tanks, but sports a kit much more neatly aligned to an aggressive/protective hybrid build. As a result, Sigma is incredibly difficult to play well, let alone master. Fortunately, we've taken the liberty to document the most effective ways of playing Sigma, all of which are tidily collected below.
Overwatch Sigma abilities and ultimate
Sigma's abilities aren't particularly accessible when considered alongside those of other tanks, which is likely why he boasts a difficulty rating of three stars. As a result, mastering him is no easy feat. His most essential ability is his Experimental Barrier, which is a deployable shield that follows a forward trajectory. Sigma can opt to halt the shield in place wherever he chooses, which means you can safely protect your teammates in some innovative and unpredictable ways. He can also recall the shield at any given time and instantly redeploy it in a new direction, as the ability only goes on cooldown after the shield has shattered. Be sure to recall it when it's in danger of breaking, as, similarly to Reinhardt's shield, it only regenerates when it's not in use.
Accretion is a massively powerful offensive ability that sees Sigma pull a gargantuan chunk of debris out of thin air before hurling it towards enemy lines. It has a long casting time, so you shouldn't trigger it if you're in a position of vulnerability, and an even longer cooldown, which means you should only use it sparingly. Accretion deals splash damage, but actively knocks down enemies with whom it makes direct impact. Interestingly, it can even be used to interrupt enemy Ultimates, like Brigitte's Whip Shot or McCree's Flashbang. As a result, it's best to reserve Accretion for situations in which you can benefit from maximum utility. Given the fact that Sigma's primary weapon, Hyperspheres, already deals a decent amount of damage, there's really no need to be impulsively wasteful with Accretion.
Sigma's Kinetic Grasp is one of the most unique abilities in the game, converting 40% of damage from incoming projectiles into shields. This can be used to make up for his limited mobility, as it can allow you to safely close the gap with an enemy while subsequently entering the engagement with a drastically increased health pool.
Gravitic Flux is Sigma's Ultimate, which creates a sort of black hole that raises all enemies within its circumference into the air, where they're helplessly suspended for several seconds before being devastatingly slammed into the ground. The initial raise only deals 50 damage, but the subsequent slam strips affected heroes of 50% of their maximum HP. Sigma can continue to attack enemies while they're in the air, and combined with complementary fire from your team, Gravitic Flux has the potential to result in a quick and clean team kill. Gravitic Flux also grants Sigma the ability of flight, which can be manipulated into providing him passage to otherwise inaccessible positions and flank routes.
Overwatch Sigma tips and tricks
Know your weapon: Sigma's primary weapon, Hyperspheres, deals significant damage but is incredibly difficult to use effectively. Essentially, Hyperspheres enables Sigma to cast out two orbs which have similar properties to Moira's Biotic Orbs, in that they bounce off hard surfaces and change direction based on the angle of contact. However, it's perhaps most beneficial to chase direct hits, as these treacherous spheres explode on enemy impact. They're a little slow, and have quite a short range, but you'll hopefully be able to mitigate both of these issues by using your Experimental Barrier and/or Kinetic Grasp with nuance.
Know who counters Sigma: Given that Sigma is still relatively new, his place in the meta at large remains ambiguous outside of the professional circuit. However, Sigma has next to no way of contesting opponents at range, and has an absolutely massive hitbox, so he definitely doesn't like snipers like Hanzo or Widowmaker, and has no way of dealing with an airborne Pharah. He's also quite fragile relative to other tanks outside of the buffs provided by his abilities, so if you're inhibited by cooldowns you'll make easy prey for tank-busters like Reaper. A clever Sigma player shouldn't be countered too hard, but given his abnormally high skill ceiling, untouchable Sigmas are few and far between.
Best strategies for Sigma: The most optimal way of performing to a high standard as Sigma is to immediately determine your preference of playstyle and commit to it. Because of his offensive/defensive hybrid build, Sigma can either act as a heavy-hitter or a protective main tank. The latter should definitely take precedence, as his uniquely mobile shield and ability to mitigate enemy attacks with Kinetic Grasp allow him to very effectively take care of friendly supports. Playing him in this way should beget naturally-closing gaps on the battlefield, which will allow you and your hopefully healthy teammates to wreck shop once you're within Hyperspheres range. Just remember that you should prioritize tanking for your team, so don't be shaken by insecurity stemming from an apparent lack of consistent damage-dealing on your behalf. Emphasize protection, and hurl rocks at your helpless enemies with Accretion when it's safe for both you and your team to do so.
Heroes with the best synergy with Sigma: Sigma's Experimental Barrier makes him a dream come true for mobile heroes who get little to no utility from the stationary shields boasted by Reinhardt and Orisa. If your D.Va is diving the enemy team, your shield will protect her throughout the course of her approach, allowing her to instigate the engagement while still at full health. Sigma's other main synergy is tied to his Ultimate, which works beautifully in tandem with DPS Ultimates by priming enemies as stunned, immobile targets. A friendly Barrage should annihilate a team suspended with Gravitic Flux, while enemies post-slam make easy targets for a devastating Dragonblade. The key to playing Sigma well is to focus on coordinating with your teammates, both offensively and defensively, and knowing the difference between when you should protect your supports and when you should ride at the vanguard into an all-out-attack.