Psycho Knife

The Psycho Knife is a Hardmode, post-Plantera melee weapon that has a 2.5% / (1/40 / ) chance to be dropped by the Psycho during the Solar Eclipse event. When holding the Psycho Knife and standing still, the player will quickly enter stealth mode, causing them to turn almost completely transparent, move much slower, and no longer be targeted by enemies.

Stealth mode is engaged gradually over the course of about one second, during which the weapon's stats are steadily boosted up to the following values:
 * Damage +300%: 280 (from 70)
 * Critical chance +30: 34% (from 4%)
 * Knockback +100%: 7 "Strong" (from 3.5 "Weak")

Stealth mode is disengaged when successfully attacking an enemy or when switching to a different weapon. Swinging the weapon alone does not cancel stealth, nor does walking or flying. Standing still again afterward re-engages it. Moving or swinging the weapon during the one-second transition period, however, will cancel stealth mode.

Its best Modifier is Legendary.

History
Couteau de Psycho 사이코 칼