His gear is available from his Challenge (level 1) or Raid completion rewards (level depends on difficulty).
Grandmaster of the Lin Kuei, Sub-Zero can create a clone of his opponent to fight for him in battle. Also, using an ice ball, he may freeze his opponent, stopping the victim's power generation and allowing for a follow-up attack from himself or one of his teammates.
Sub-Zero is incredibly powerful when facing opponents with much higher stats, particularly those with weak passives. His ice clone essentially steals most their stats for his use. In fact, his worst enemy is often the countdown timer, especially against high defence teams; however, it seems as long as his team does more damage, he can still win in Arena matches when the time runs out.
Normally, you're invulnerable and the enemy can't start a special while you're using a special. However, if Sub-Zero is far away from his opponent, Klone Toss would take a long time to reach his opponent and the latter would be able to use ranged basic attacks, or if far enough, a ranged special or a Supermove before it could hit. The basic attack can KO Sub-Zero, preventing a clone from being created (although they would still be briefly frozen). A special or supermove (or in rare occasions, a well-timed tag) would negate Klone Toss entirely.
When the countdown timer runs out in Arena, if you win with a clone, the game would automatically tag in Sub-Zero to perform the winning animation. This led to a misconception that you must tag out the clone at the last moment to win, which is not the case.
Since Doctor Fate/Power Girl is practically mandatory for him anyway, a different strategy is to chain his Ice Balls; by freezing them, waiting till they are about to be unfrozen before hitting them with basic attacks and freezing them again, you can lock down enemies almost indefinitely (especially with high level Ice Ball that increases freeze duration, e.g. by level 41 it is doubled, and in later parts of the match with faster power generation). Ice Ball used on a target that isn't being hit by basic attacks or already frozen can be blocked or even jumped over, however.
While clones is generally a much better strategy against stronger opponents, this could be useful in some situations, for example, against an enemy Sub-Zero clone, which cannot be cloned. If you clone an enemy Sub-Zero, the clone can use Klone Toss, but cannot create another clone.
Even when using the clone strategy solely (which has a hidden advantage of not needing expensive upgrades, as the vast majority of the damage dealt would be by the clone, not the toss), having Ice Ball at least 1 level higher can protect Klone Toss from being disabled by Silver Banshee. Note that upgrading Klone Toss has no effect other than increasing its low inherent damage, so it is not very useful.
Both Ice Ball and Klone Toss (the special itself) cannot deal a KO blow.
When relying on the clone strategy, any offensive stat on Sub-Zero himself is basically useless. Instead, defence can be somewhat helpful for Sub-Zero to survive if he is caught without a clone.
- Power generators/cost reducers: Doctor Fate, Power Girl or Emerald Green Lantern is good for him due to his power reliance. Doctor Fate is especially good because of his infinite 3-hit ranged combo than can pin down opponents without ranged specials. Normally this runs the risk of taking a supermove, but Sub-Zero can tank it with a clone.
- The Joker: Especially when facing extremely strong opponents, the combat capabilities of the third hero (other than Sub-Zero and Doctor Fate) becomes less relevant and The Joker can still be useful suicide-bombing with his passive, giving you 1 bar of power and stunning the opponent, giving you breathing room and vitally, interrupts specials that can normally deal multiple KO blows and would otherwise hit Sub-Zero.
- Heroes with strong effects that do not rely on their passives or supermoves.
- Heroes with Special block, such as Wonder Woman, Gorilla Grodd, Superman, and their variants. However, if special blocked, the ice clone will not freeze the target, reducing your time to react. Especially noticeable since using Klone Toss, like all specials, incur a global special cooldown - if Sub-Zero's opponent is not frozen, they can immediately use a special to KO the clone, and if you have the cooldown you can't block it with the clone's special block.
- Black Adam: When cloned, his Electric Burst Ability still has a chance to steal power bars, and Lighting Cage can still activate the power cost reduction buff. Note that if Doctor Fate, Power Girl, or Black Adam are on Sub-Zero's team, they do not affect his clone, but a Black Adam clone can activate its own power cost reduction buff that will apply to Sub-Zero and his team as well while it lasts, but if the clone is tagged out and another clone is summoned, the second clone will not get the buff.
- Shazam: Sub-Zero's clone can use Shazam's Roaring Strike for massive team healing (including both the clone and Sub-Zero).
- Soulstealer Doctor Fate: He may waste his supermove and passive against Sub-Zero's clone; as the clone is created at low health, Soulstealer Doctor Fate would likely damage himself and heal the clone, and if the clone has high defence it might even survive the super. Sub-Zero's clone can heal itself using his Break of Life, however, the heal is very low and inefficient.
- Heroes with good specials that can deal multiple KO blows (so it could KO the clone and also hit Sub-Zero), one example being Multiverse The Flash's special 3.
- Last Laugh The Joker: a clone being KO'ed will activate Joker's passive, giving him bonus damage.
- Horrific Scarecrow: Increases his power costs, which cripples his effectiveness.
- Justice League Batman: His passive allows all Justice League teammates to ignore one special, which prevents Sub-Zero from creating a clone.
- Armored Superman: Same as Justice League Batman, but he only ignores one special for himself.
- Black Adam: Same as Horrific Scarecrow, but more randomly from specials. His Lightning Cage buff (reduces Black Adam's team's power cost by 3) and Electric Burst's power steal is also very difficult for Sub-Zero to handle.
- Unlike in the first game where Scorpion lacks a "prime" version and starts with a card entitled "Mortal Kombat", both Sub-Zero and Raiden go without the title in Injustice 2 Mobile.
- Ice clones also have various animations that are recoloured for the ice palette. Those that are so recoloured are those they are considered part of the hero's "model", e.g. ice clones of Atrocitus will have an ice-textured Dex-Starr when the latter is summoned. "Energy effects" like Dex-Starr's ranged projectile is not affected and would still look like the original.