Using a Shield Gears|Gear on Gray is a good idea in combination with his Fake Injury Star Power, since Gray is always at full health as long as his Gear's shield is up, meaning all hits he takes will stay reduced by 50% until he takes a hit without a shield up.
Be wary when using his Super because Gray can accidentally teleport in front of a high damaging Brawler such as Darryl or Bull. This can be prevented by manually aiming his Super away from close range Brawlers.
In Solo Showdown, you should save your super as a last resort when you need to escape from a tight situation. The Super activation is instant and unlike the regular teleport, enemies can't use the dimensional door.
His attack reload is slow and his bullets are delayed so it is best to aim your attacks rather than auto aiming.
In Heist, Gray can put his Super near the enemies' safe, so that teammates can quickly teleport to the safe to do damage and/or quickly escape from defending enemies.
This can be devastating to the enemies' safe when used by teammates such as Buzz and Spike, as they can quickly melt the enemies' safe, and the enemies are pressured to defend both the teleporter and the safe.
By using his Walking Cane Gadget, Gray can finish off low health brawlers hiding behind walls, or can even disarm enemies holding the ball in Brawl Ball.
Teleporting while pulling an enemy with Gray's Walking Cane Gadget can allow the pull range to be extended to Gray's initial position before teleporting, allowing the player to bring high-focus targets like a Gem carrier closer to your team.
While camping near Gray's teleporters is a viable strategy to ambush him or his teammates, do note that if you stand too close to one they will begin to glow similarly to when they are being activated, betraying your location.
Changelog
12/12/22 Gray can be unlocked by completing a special quest required to deal 500,000 damage points until 02/01/23. The Runaway Gray skin was added.
26/12/22 Gray's Grand Piano Gadget and New Perspective Star Power were added.
02/01/23 Gray became available in the Starr Road.
12/01/23 Gray's Grand Piano Gadget radius was decreased to 2 tiles (from 4).
28/02/23 Gray's Super no longer teleports his allies instantly. Gray's main attack visual effects were reworked. Gray's True Silver and True Gold skins were added.
08/03/23 Fixed a bug where Gray's Super would rarely crash the game.
09/03/23 The Detective and Detective Gray (Noir Edition) skins were added. They were featured as License to Brawl skins.
25/04/23 Fixed an issue with Detective Gray (Noir Edition)'s Super visual effects.
27/04/23 Fixed an issue with Gray's Star Power localization. Fixed an issue where the Detective Gray (Noir Edition) skin could be bought without owning the Detective Gray skin.
27/06/23 Gray's Fake Injury Star Power damage reduction was increased to 50% (from 25%).
05/09/23 All Brawlers' health and damage were increased from 5% to 10% with each Power Level.
24/10/23 Gray's New Perspective Star Power healing was increased to 1188 (from 1000) and now scales with Power Levels. Gray's flavor text was changed from "What's the meaning of Orthochromatic? Gray would tell you, but he doesn't speak much." to "Gray styles himself as a character in an old silent film. He takes the act seriously but sometimes forgets to keep his mouth shut when doing finger bullets."