得勝而回 Back Again in High Spirits
八戒回頭，就不見那些小行者，道：「哥哥的法相兒都去了。」行者道：「我已收來也。」八戒道：「妙啊，妙啊！」兩個喜喜歡歡，得勝而回。八戒回头，就不见那些小行者，道：「哥哥的法相儿都去了。」行者道：「我已收来也。」八戒道：「妙啊，妙啊！」两个喜喜欢欢，得胜而回。
逐句解 Line by line
Bajie turned his head and could no longer see those little Pilgrims, and said, "All my brother's forms are gone."
法相 is a form produced by magic, and 相 is xiàng there — an appearance, a look. Bajie has been fighting shoulder to shoulder with two hundred copies of his brother and noticed their disappearance only afterwards.
Pilgrim said, "I have already taken them back in."
Eight characters, delivered with the flatness of a man putting his tools away. The hairs go back on his body and the army ceases to exist.
Bajie said, "Wonderful! Wonderful!"
Seven characters of uncomplicated delight. Bajie's reaction to a trick he has seen his brother do many times before is to be impressed all over again, which is one of the more likeable things about him.
The two of them, in high spirits, came back in victory.
得勝, to win, is a set compound, and 得 keeps its full dé there rather than becoming the little hinge. 喜喜歡歡 doubles both characters of the ordinary word for happy, which makes it bouncier — and it is the last cheerful line before the chapter shuts a door in their faces.
The scene ends on victory and the victory is worthless. They have killed the vanguard, scattered the troops and driven the king back into his hole, and they are no closer to the master than when they started.
The novel is doing something deliberate with the pacing here. It gives the reader a battle won, a comic exchange and two brothers walking back pleased with themselves — and then, in the very next passage, blocks the door with rubble. The high spirits exist to be punctured.