I'm working this as a reference to ultrakill cause it just feels right
Exotic Player Upgrade
CQC-TrainingV1.exe
"When timed right, your melee can now parry some attacks, negating their damage"
Mainly physical attacks, but can also parry those elemental bubble launchers. If you parry a projectile it sends the projectile backwards. If you parry a physical attack you'r flung backwards. The distance you're flung scales with the damage you would've taken.
Exotic Player Upgrade
CQC-TrainingV2.exe
"Hold the melee key to charge a more powerful strike. Warning: overcharging may damage your unit"
When you hold the melee key you charge your fist, on release you do a melee attack that is stronger and has a bit of AoE.
If you hold it for too long (indicated by your arm looking "overcharged") it will instead explode. The explosion deals massive damage to you and anyone nearby. Damage done to you should not be an insta kill, but leave you on red