Using his T-Bone Injector in Heist is usually a good choice, since Bull relies on the length of his Super to reach the Heist safe from a far distance away, so using Stomper is redundant. T-Bone Injector also allows Bull to stay in the fight longer, which allows just enough time to deal a large fraction of the safe's health.
Bull is very useful in Heist, as he can rush over water and break the obstacles in front of the enemy safe. The opening that he creates by his Super can also be utilized by teammates to attack the safe. He's also viable in the mode with his heavy damage at point-blank range, which can be utilized to destroy the safe easily.
Bull's Berserker Star Power doubles his reload speed, allowing Bull to have one of the highest overall damage outputs of any Brawler. Bull can use this power to dominate the robots in Boss Fight and Robo Rumble. Bull is also an ideal Power Cube Carrier in Boss Fight and a solid Brawler in Takedown, as you can use the Power Cubes and Bull's high burst damage to engage the Big Boss, while surviving longer with his T-Bone Injector Gadget and his Tough Guy Star Power and his high health, or to defeat the Boss quicker with his Berserker Star Power and Stomper Gadget, respectively. You can also use this in Heist if you happen to be fairly low on health whilst approaching the safe to incinerate the enemy safe. While he is the Boss in Big Game, you can also use this as an extra boost to his damage output, though being the Boss already boosts your reload speed tremendously.
Bull is also effective in Brawl Ball with his high health and Super that destroys obstacles, because he can easily clear openings in the map, assisting his teammates in scoring. He can also self-pass, by kicking the Ball forward and charging towards it, then attempting to score. However, avoid using your Super to make enemies lose the ball by knocking them back, as he can break your team's goalpost and other vital walls, as this only assists the enemies and allows them freely to retrieve the ball and score. Instead, burst your attacks on them at close-range to quickly defeat them with your high damage.
Recommended Build
Bull's T-Bone Injector Gadget is extremely useful to heal up when in danger, especially if you don't have your Super to escape or don't have healers on your team, and it can also allow you to tank damage effectively.
Use Bull's Stomper Gadget to catch flanking enemies by surprise. Bull's high burst damage will allow him to get shots before an enemy can react. In some cases, Stomper can also cancel Supers that will inadvertently lead you into danger or Supers that enemies have already countered.
Strategies
Bull's Super allows him to charge a very long distance in any direction, destroying all obstacles in his way. Since Bull can deal maximum damage when he's close to his target, this ability can be used for getting Bull close enough to enemies to defeat them. Make sure to aim you Super correctly and predict the enemy's movement, so you can reach the enemy properly to defeat them, or use his Stomper Gadget to get as close as possible to the enemy. Bull's Super can also come in handy when Bull needs to escape from enemies if in danger because of his Super's long charging distance, which is useful in Bounty when overwhelmed by enemies. However, he's not impervious to damage while charging, so be wary of nearby enemies. Also, be careful in Showdown when escaping as his Super's long distance may force you into the poison clouds, however, this can be circumvented with his Stomper Gadget to interrupt his charge.
Other
Bull can deal a lot of damage when he's within close-quarters of his target and has high health, but can't deal maximum damage when he isn't close. Take advantage of bushes, obstacles, or thin choke points to ambush and defeat enemies. Therefore, in more open areas or maps, try to dodge enemy attacks. Bull has a higher movement speed than most Brawlers so he can rush enemies and avoid their attacks more easily. It's ideal to dodge enemy attacks and not tank damage, as that allows enemies to quickly charge their Supers.
Bull fares well with throwers who are great at area control such as Barley or Tick, especially in Duo Showdown. They can annoy enemies by placing their attacks everywhere, and Bull, being a Brawler with high health and a high damage output, can quickly finish those enemies off.
Changelog
16/08/17 Bull's reload time was increased to 1.6 seconds (from 1.5).
07/12/17 Bull's Berserker Star Power was added. he health and damage statistics of all Brawlers were multiplied by 4.
18/12/17 Bull's health was increased to 5000 (from 4800). His main attack damage was increased to 440 (from 400) per shell. His Berserker Star Power now triggers at 50% health (from 30%).
22/12/17 Bull's movement speed was increased to 700 (from 650). His health was increased to 5400 (from 5000).
16/01/18 Bull's health was decreased to 5200 (from 5400). His Berserker Star Power now triggers at 40% health (from 50%).
27/01/18 Bull's health was decreased to 5000 (from 5200). The number of hits necessary to charge his Super was increased to 10 hits (from 8).
21/03/18 Bull's main attack damage was decreased to 400 (from 440) per shell. Every Brawler's movement speed was increased by 70 points, increasing Bull's movement speed to 770 (from 700). All Brawlers' projectile speeds were increased by 9%.
05/12/18 Bull's health was increased to 5200 (from 5000). Bull and Viking Bull were remodeled. Viking Bull now costs 80 Gems (from 30).
01/02/19 The Touchdown Bull skin was added.
26/06/19 The Linebacker Bull skin was added.
10/07/19 Bull's Tough Guy Star Power was added.
29/08/19 Bull's animations were reworked.
07/11/19 Bull's health was decreased to 4900 (from 5200).
17/03/20 Bull's T-Bone Injector Gadget was added.
13/05/20 The Barbarian King Bull skin was added to the game until 01/07/20. It was a gift to celebrate Supercell's 10th Anniversary.
08/07/20 The design on the back of Bull's jacket was altered.
10/09/20 Bull's health was increased to 5000 (from 4900). His Super charge rate was increased sligthly. His Super recharge rate was also increased from his Super.
22/10/20 Bull's True Silver and True Gold skins were added.
23/10/20 Bull's Stomper Gadget was added.
15/12/20 Bull's Berserker Star Power now triggers at 60% health (from 40%).
27/01/21 Bull, Barbarian King Bull, Viking Bull, Touchdown Bull, and Linebacker Bull received facial animations.
12/02/21 The Space Ox Bull skin was added. It was featured as a Lunar Brawl 2021 skin.
16/06/21 Bull gained a Trait where he can now charge his Super from receiving damage.
17/06/21 The Super charge rate from his Trait was decreased to 20% (from 30%).
25/08/21 The Super charge rate from his Trait is now based on Bull's max health.
27/10/21 Bull's class was changed to Tank (from Heavyweight).
08/11/21 The B-800 skin was added. It was featured as a Brawl Pass Season 9 exclusive skin.
02/03/22 The Lion Bull skin was added. It was featured as a Club League skin.
27/04/22 Viking Bull's main attack and Super visual effects were reworked.
29/07/22 The Bull Mang skin was added. It was featured as a BT21 skin.
12/12/22 Bull's Super damage was increased to 960 (from 800). Bull's rarity was changed to Rare (from Common).
28/02/23 Bull, Touchdown Bull, and Linebacker Bull's main attack visual effects were slightly reworked.
11/03/23 The Alleycat Bull skin was added. It was featured as a License to Brawl skin.
25/04/23 Linebacker Bull now costs 29 Gems (from 2500 Star Points).
15/08/23 Bull's main attack damage was increased to 440 (from 400) per shell. Bull's Super charge rate was increased slightly.
05/09/23 All Brawlers' health and damage were increased from 5% to 10% with each Power Level. Bull was slightly remodeled. Bull's Jaws of Steel Hypercharge was added.
07/09/23 Fixed an issue with Bull having damage reduction outside of his Hypercharge state.
24/10/23 Bull's T-Bone Injector Gadget healing was increased to 1600 (from 1500) and now scales with Power Levels. Lion Bull now costs 149 Gems (from 2500 Club Games Bull's flavor text was changed from "Bull deals massive damage up close with his shotgun. For his Super move, he charges through barriers and knocks back enemies!" to "Bull isn't as carefree as he was in his youth, but just because his rowdy days are behind him doesn't mean he won't still crush someone who's asking for it."
27/02/24 Bull's Jaws of Steel Hypercharge multiplier was decreased to 35% (from 40%). Bull's Jaws of Steel Hypercharge damage boost was decreased to 5% (from 10%). Bull's Jaws of Steel Hypercharge shield boost was decreased to 25% (from 30%). All Brawlers' Hypercharges duration can no longer be extended. Bull's True Silver and True Gold skins were slightly remodeled.