The Pilgrim and Eight Rules raised their heads to look, and beheld the creature:

但見那怪物, "and beheld the creature," is the narrator clearing his throat before a set-piece. The portrait that follows is a formal descriptive piece, and the cue stays with the prose rather than counting as its first line. 觀看 takes guān, the looking-at sense, not the guàn that names a Daoist temple.

His face, as if powdered, three parts white; his lips, as though rouged — a very figure of parts.

The portrait opens on beauty, not menace -- a face powdered white, lips as if rouged. 三分白 is "three parts white," a fraction, so 分 is fēn. Worth noticing: the same character was fèn back in the opening song, in 隨分, where it meant your allotted share. Fraction keeps the everyday sound; portion takes the other. 一表才 is a clipped form of 一表人才, a fine figure of a man -- a compliment, applied here to something that eats monks.

Temple-locks coiled like blue cloud, shaming the indigo dye; brows parted like a new moon, as though cut with a blade.

Two matched lines on hair and brow. Temple-locks coiled dark enough to shame indigo; brows curved like a new moon and as clean as a knife-cut. 眉分新月 uses 分 in its plain sense of parting or dividing, fēn again. 靛 diàn is indigo dye, the deepest blue a Ming dyer could get.

His battle-skirt finely worked with coiling dragon and phoenix; his frame, beside Nezha's, yet fuller and rounder.

Here is the comparison the whole portrait has been building toward. 哪吒 is Nezha, the boy-god of Chinese myth -- a child with a warrior's power, third son of a heavenly marshal, and the standard figure for the divine child. Setting Red Boy beside him is not idle praise. Red Boy is Nezha's dark twin: same youth, same terrible strength, opposite side. 更 is gèng, "yet more," and 富胎 (a form of 富態) means full-fleshed, well-covered -- he is the rounder, plumper child of the two.

Both hands gripping the spear, his menace bitter and cold; auspicious light guarding his body, he came out from the gate.

雙手綽槍, both hands snatching up the spear. 綽 is read chāo, the vernacular grabbing verb, not the chuò that means ample or spacious. This is the chapter's first of two, and the second, a few lines on, uses the same verb on something you cannot grab. 凜冽 is a cold that bites. 祥光, auspicious light, is the halo of a being with real standing in the spirit world -- the novel granting a monster a genuine aura.

His fierce cry rang like the roar of spring thunder; his glaring eyes flashed bright and quick as darting lightning.

Sound and sight, paired. A cry like spring thunder, eyes flashing like lightning. 哏 gén is a gruff, snarling noise. 掣電 is lightning in the act of darting, 掣 chè meaning to pull sharply. 乖 guāi sits in the rhyme slot and means quick and nimble here, not the "well-behaved" sense a modern reader knows.

Would you know this demon's true name and style? — famed a thousand ages, he is called Red Boy.

The closing formula of a portrait piece: would you know his name? -- and then the name. 紅孩 is Red Boy, more fully 紅孩兒. Withholding the name until the last line is the convention, and it lands harder for the delay: all that beauty and lightning belongs to a child.