You should always hold your Primary skill down. Laser Sword combos are not interrupted by your non-Primary skills, sprinting, or jumping, allowing you to slash while using Whirlwind, Blinding Assault, and Eviscerate. A Laser Sword combo will, however, only start when you are not in the middle of using another skill.
Whirlwind Can be used on slanted edges / ramps that you can walk up to launch the player vertically.
Whirlwind when used on the ground dashes you forward, when used in the air it acts like a double jump. Use it in the air to stay airborne, but use it on the ground to be evasive as it covers more distance faster.
There is a short delay before attacking again after the third hit in the Laser Sword combo. Activating Whirlwind immediately after the hit connects can cancel this delay.
When fighting bosses, Mercenary can stay safely in the air above their heads for a very long time by chaining together Whirlwind->Eviscerate->Whirlwind along with laser sword attacks and double jumps.
Your Blinding Assault cooldown reset leaves just enough time to use Laser Sword twice or combo Whirlwind + Laser Sword before you need to dash again. You have just enough time to Eviscerate between Blinding Assaults, if you do it immediately without any delay between dashes.
Your longest distance jump combo is Sprint-Jump-Whirlwind-Blinding Assault-Eviscerate-Double Jump-Whirlwind.[Verify]
Prior to Build ID #3731106, Eviscerating directly into the ground when airborne would cause you to take heavy fall damage.
Mercenary's health regeneration is noticeably higher than other survivors, allowing him to recover faster than the other survivors without the use of healing items.
Some bosses have heads which act as solid platforms, which the Mercenary can stand on to resume attacking the boss without as much danger from the swarm of enemies below.
Wax Quail's boost applies for Mercenary's first two jumps, whereas other survivors can only receive the boost on their first jump, even with the Hopoo Feather
Using your Primary attack on enemies such as the Wandering Vagrant while airborne also noticeably reduces your rate of decent.
If you use Blinding Assault very close to Wandering Vagrant, you can push it into a wall at high speeds causing massive damage. This can be easily achieved if you hit directly on top of its mantle.
Blinding Assault can slam nearly any flying enemy into walls for massive damage including airborne bosses, but it cannot affect Alloy Vultures.
The damage dealt when using Blinding Assault to slam enemies into walls can receive critical hits
Slicing Winds does NOT scale with attack speed, unlike Eviscerate
It is advised to provide at least one or two Backup Magazines to the Mercenary if they have Rising Thunder because the added air time can allow them to dodge attacks even if Blinding Assault and Eviscerate are on cooldown.
Rising Thunder can still hit enemies directly below the Mercenary
Slamming smaller enemies into a ceiling with Rising Thunder can deal extra damage to them