It's Trigglypuff!

Download available at The Sonichu vs Bronies archive
https://archive.org/details/Sonichu_vs_Bronies

Music:
0:00 Jigglypuff!
0:23 Jyc Row - King Sombra ~ A Final Encounter
5:48 Serraphas3 - Power Metal Themes - I Love You - Barney
6:11 The Barney Song Metal Version!
7:11 Panic - Tree Of Harmony
10:08 Frozen Night - Inner Light