3 sentences

1. 他在万圣节派对上扮成了佐罗。

   tā zài Wàn​shèng​jié pài​duì shàng bàn​chéng le Zuǒ​luó.

   He dressed up as Zorro for the Halloween party.

   Source: Dong Chinese Dictionary

2. 他在万圣节扮成了一个吸血鬼。

   tā zài Wàn​shèng​jié bàn​chéng le yī gè xī​xuè​guǐ.

   He dressed up as a vampire for Halloween.

   Source: Dong Chinese Dictionary

3. 万圣节派对上，他穿着一件黑斗篷，把自己打扮成死神的模样。

   Wàn​shèng​jié pài​duì shàng, tā chuān zhe yī jiàn hēi dǒu​peng, bǎ zì​jǐ dǎ​ban chéng sǐ​shén de mú​yàng.

   At the Halloween party, he wore a black cloak and dressed up as the Grim Reaper.

   Source: Dong Chinese Dictionary