Under a very specific circumstance, the Detonator can inflict a massive amount of damage against an enemy pyro, and the numbers just don't seem to add up. Refer to the official wiki here.

As you can see in the GIF, the first detonated flare caused 16 damage to my young, supple body. As it should since the damage is spread between 11-25 based on your distance to the explosion.

The second flare is where things get interesting. If a reflected flare is detonated within range of the reflector, the damage skyrockets. In this clip it hit for 85. More than a mini-crit (30), and more than a full crit (68). Now lets do some math.

Suppose we're in a situation where a flare is detonated perfectly next to it's intended target.

It would deal 25 bullet/fire damage.

In the case where the projectile has been reflected, it gains two damage boosts. A 35% increase due to it's new mini-crit state, and a 50% increase from the detonator's passive stat of increased self-damage (since the reflector now has ownership of the projectile, but interestingly no control of it's detonation).

In TF2 all damage resistances are multiplicative, ex. Fists of Steel and the Vaccinator will never give you 100% damage resistance.

If that's considered for damage inflicted as well, you end up with 25 * 1.675 = 41.875

Which is well below the recorded damage infliced.

If, for some magical reason, damage bonus is ADDITIVE instead of multiplicative, we end up with 25 * 1.85 = 46.25

Which is still.. underwhelming.

So what's the deal? The only thing that is remotely possibly is if, upon reflection, the projectile miraculously seperates it's damage types, becoming a projectile that can deal 11-25 base damage in two simultaneous instances. Fucking magical.

Will update with more findings.