Minamoto-no-Raikou's NP really that weak??

In my past experiences with Raikou, her NP can be a bit hit and miss. Pretty good damage on crowds, but mediocre vs single bosses.
Isn't her damage kind of meant to come from buster crits, rather than NP?

For reference, my Raikou is lvl 96 NP1, +990/+990 fluffed out, 5-6 (+25% buster) -8 (+44% dmg boost vs most targets) and usually runs with either MLB Holy night supper (+15% np and crit damage) or MLB Joint Recital (+20% Buster and crit damage).
Her NP damage might be equal to 90 NP5 Kiyohime (sorry, can't compare as mine is at 70) in that it does 40-60k+ per target.
But the buster crits can do roughly 40-70k+ per attack. Heck, if they crit, I saw her Quick cards do 10-15k damage and Arts crits pulled off around 30k per card.
With a crit-star supplier, I'd say her average brave chain can do roughly twice her NP damage?
Just my 2 cents in the matter.

NP5 is a hell of a drug, especially if you've put four grails into your Kiyohime. For reference, AoE NP5 is generally as strong as single target NP1. It's not that Raikou is weak, per se, but just that NP5 is extremely strong - if you were to hypothetically have NP5 Raikou, she'd casually outdamage your Kiyohime by virtue of her enormously larger Attack stat.

As the above poster said, Raikou’s serious damage comes from her ability to Buster Crit. Also, her 3rd skill is key. Her damage greatly increases against demonic enemies and servants with earth and sky traits, which covers a pretty good range.

Use her NP on a wave of 3 enemies and she’ll generate 25+ stars from her NP alone. Her 1st skill increases her star absorption for 3 turns and her buffs from her 3rd skill last for 3 turns as well. With a consistent supply of stars she is devestating. Much more so than Kiyohime.

When Raikou was first introduced I also had no interest in her and thought of her as nothing more than a daily farmer. But use her right and she’s absolutely a boss killer and one of the strongest beserkers.