Desmоnd

Ыхыхыхы.

1. Environmental Factors Working Against the Monowire
(1) Wind & Air Resistance
Problem:

A monofilament wire (even magically thin) has mass and drag.

In an open, windy environment, it would:

Deform unpredictably (like a kite string in a breeze).

Fail to maintain tension (sagging or tangling).

HJPEV’s precise cuts would be impossible—wind would push the wire off-course.

HPMOR Handwave:

Magic might "ignore" air resistance, but the story never states this.

(2) Breath & Movement
Problem:

HJPEV is breathing heavily (post-Portkey disorientation, stress).

His chest movements would jostle the wire, ruining aim.

Even a slight cough could make the wire wobble into his own body.

HPMOR Oversight:

No mention of breath control (a basic marksmanship skill).

(3) Visibility (Moonlight Glint)
Problem:

The wire is explicitly described as visible in moonlight.

Yet no Death Eater notices a shimmering line cutting through them.

Realistically:

A thin wire in motion catches light constantly.

Even untrained thugs would see the glint and dodge.

HPMOR Excuse:

Death Eaters are "distracted"—but this is plot-induced incompetence.

2. The Near-Impossibility of Controlling the Monowire
(1) Arbitrary Trajectory? No.
Monowires are not lightsabers—they don’t cut on contact unless:

Tension is maintained (needs anchor points, like a garrote).

Motion is controlled (e.g., pulled straight, not floating).

HJPEV’s Use:

He somehow whips it in a perfect arc through multiple targets.

Realistically, this would require:

Two fixed anchors (e.g., trees, walls)—but there are none.

Precise telekinesis (which he lacks).

(2) Cutting Efficiency Issues
Monowires kill via tension + motion (like a cheese slicer).

A loose wire (floating in wind) would glance off clothing/armor.

Death Eaters wear robes—fabric would snag, not cleanly slice.

HPMOR’s Version:

Acts like an omnidirectional laser, which isn’t how wires work.

(3) Risk of Self-Injury
Problem:

A monowire under tension would recoil if cut loose.

HJPEV is surrounded—any slip could decapitate himself.

Ignored in Story:

No safety measures (e.g., anchoring, recoil planning).

How the Scene Should Have Worked
For HJPEV’s trick to be plausible:

Anchor Points: Use fixed objects (trees, rocks) to tension the wire.

Stealth Setup: Pre-place the wire before the fight (not mid-combat).

Wind Mitigation: Cast a localized air-shield spell to stabilize it.

Realistic Limits: Accept that some Death Eaters would dodge.

Instead, we get magic-waved perfection—the antithesis of "rational" fiction.