Dio: Pft, H-Holly! Holly, get over here. You've gotta see this!
Holly: D, Im in the middle of something. What do you want?
Dio: Papa's…. Check out what papa's wearing. [holds in laughter]
Holly: What is… Papa, what are you wearing?
Sombra: Ah, your lord father insisted This king try and … modernize our attire. [Grimaces] This is what I found.
Dio: I told you! He looks like an emo!
Holly: Papa! I told you, let me pick your clothes. Ugh, this is so embarrassing.
Fluttershy: Holly? Is something wrong-
Sombra: Ah, my Lady wife, good day to you.
Fluttershy: You…clothes…
Sombra: Ah, our offspring have informed This King that this is not suitable for the modern age.
Fluttershy: I… I really…
*
Fluttershy really likes the outfit.
Sombra, like more ponies of old, tends to wear clothes and feels uncomfortable when he's not wearing anything. As such, he sticks our since only those who are old fashioned wear clothes. Despite that, Sombra chooses to keep the tradition and covers up daily. This makes his children amused as they try and get him to wear other kind of clothes.
This time, Iron Will suggested Sombra try on clothes from this generation and after a trip to Not Topic, his wardrobe had shifted centuries forward.
Note: Sometime ago, someone commented that I draw Sombra like an emo so I thought, why not make him dress the part. I admit, I drew this from memory so he looks more like a rocker than a goth so… yeah.