One thing is for sure: He didn't create the angel in this movie!
Here's a good article on the nature & role of angels. While we will never really know why God created this non-human order of being, we can examine their activities to get an idea. The following is an excerpt from the fore-mentioned website.
[Answered by Pastor HM]
They praise God (Psalm 148:1-2; Isaiah 6:3). They worship God (Hebrews 1:6; Revelation 5:8-13). They rejoice in what God does (Job 38:6-7). They serve God (Psalm 103:20; Revelation 22:9). They appear before God (Job 1:6; 2:1). They are instruments of God's judgments (Revelation 7:1; 8:2). They bring answers to prayer (Acts 12:5-10). They aid in winning people to Christ (Acts 8:26; 10:3). They observe Christian order, work, and suffering (1 Corinthians 4:9; 11:10; Ephesians 3:10; 1 Peter 1:12). They encourage in times of danger (Acts 27:23-24). They care for the righteous at the time of death (Luke 16:22).