These are some of my accomplishments that I am very proud of.

I beat Gogo in FFV (Anthology) by reducing his HP to 0. My characters were about level 45.

I beat Omega Weapon in FFVIII before he was able to use his 4th attack. Didn't even need a Holy War/Invincible Moon.

I beat Ozma with a party average level of about 55.

I beat The Undying with a party average level of about 45 and beat Zodiark with an average level of 65. This was all done on Active on my first playthrough.

And finally, being better than Goldenboko at FF, otherwise he would have never beaten VI,VII,VIII,or IX.

Soloing Ultima Weapon in FFVIII with the speed cranked.

WITHOUT USING ZELL OR SQUALL OR SUMMONS.
But wouldn't Light Pillar kill you in one hit? How did you do it; did you use a Hero/Holy War/Invincible Moon or The End? Maybe Irvine's Shot or Rinoa's Wishing Star?