AC97
It was _highly_ personal with those three.
Chrysalis had kidnapped Twilighert's foalsitter the first time, had gotten _her older brother_ involved with her evil plans, and she watched Celestia get hurt in a fight with her. The second time around, Chrysalis had her and her friends and family kidnapped, including _her baby niece_, and she'd ended that by swearing revenge on one of her close friends (Starlight) _especially._
Tirek *_blew Twilighert's house up_*, tricked Discord into betraying them (extra personal points to Fluttershy on that one), and pushed her into a "give me all of that magic or your friends die" kind of hostage scenario, including Spike. Later, it was his knowledge that helped Cozy Glow to pull off her scheme, and he did it for _amusement,_ even though he'd personally gain nothing but the satisfaction of them being tricked.
Cozy Glow: Twilight really appreciated her as an assistant. She "loved her.":https://derpicdn.net/img/view/2018/10/15/1857084__safe_screencap_cozy+glow_twilight+sparkle_school+raze_alicorn_book_female_filly_hug_notepad_pegasus_pony_saddle+bag_twilight+sparkle+%28alicor.jpeg All of her friends did as well, they all trusted her. And Cozy Glow repaid all of their kindness with naught but treachery, arguably to the point of "attempted murder":https://derpicdn.net/img/view/2018/10/20/1861239__safe_screencap_rainbow+dash_sandbar_starlight+glimmer_yona_school+raze_falling_friendship+student.png, and in any case, she didn't care. And she learned that she purely did it out of an extremely desire to be more powerful than her.
So yeah, all of that is more compelling than "Twilight and her friends are in my way." And that's all he could ever be, unless they did some other twist entirely, because not even Celestia and Luna encountered him, on account of not being born then.
Grogar wasn't the most interesting one on any measuring stick, by design. Those three were getting screentime, _they_ got the villain song, and _they_ had personalities that weren't nondescript.
Chrysalis had kidnapped Twiligh
Tirek *_blew Twiligh
Cozy Glow: Twilight really appreciated her as an assistant. She "loved her.":https://derpicdn.net/img/view/2018/10/15/1857084__safe_screencap_cozy+glow_twilight+sparkle_school+raze_alicorn_book_female_filly_hug_notepad_pegasus_pony_saddle+bag_twilight+sparkle+%28alicor.jpeg All of her friends did as well, they all trusted her. And Cozy Glow repaid all of their kindness with naught but treachery, arguably to the point of "attempted murder":https://derpicdn.net/img/view/2018/10/20/1861239__safe_screencap_rainbow+dash_sandbar_starlight+glimmer_yona_school+raze_falling_friendship+student.png, and in any case, she didn't care. And she learned that she purely did it out of an extremely desire to be more powerful than her.
So yeah, all of that is more compelling than "Twilight and her friends are in my way." And that's all he could ever be, unless they did some other twist entirely, because not even Celestia and Luna encountered him, on account of not being born then.
Grogar wasn't the most interesting one on any measuring stick, by design. Those three were getting screentime, _they_ got the villain song, and _they_ had personalities that weren't nondescript.