I mean I love the series and setting but WTF.

Large planet level MFTL Cirno? Seriously?

She was unable to freeze a lake where the fuck is "large planet level" coming from?

The most impressive thing done with magic (that can be kind of quantified) that I know of was changing the orbit of the moon slightly.

The highest firepower "showing" that I know of is extrapolating on Yukari being said to be able to "devastate Gensokyo" to being able to life wipe a small country or The Lunarian fan said to be capable of purifying a forest on the atomic level.

Yeah there are more esoteric stuff like using dissolving the boundary between truth and fiction to get to the true moon via a reflection in a lake. But that is hard as hell to quantify.

But there is literally nothing near planetary/moon destroying. This level of fire power also dose not make sense from a narrative perspective because Marisa's Mini-Hakkero is supposed to be impressive yet on the high end it can only store enough energy to turn a mountain into ash.

There is at least a little "truth" in the MFTL component. There are three feats and I believe there is a spell card description that can be used to justify FTL speeds.

• Marisa and Watatsuki no Yorihime in SSiB. Though this one is kind of weird because in the double spark one Master Spark travels faster than the other one.

• Marisa possibly dodging a beam of light from Sunny

• Sunny Milk blocking light. Sunny is not a very strong resident of Gensokyo, though her ability is specifically to bend light so that should have been light. Though notice the other Fairies are unable to dodge the same attacks.

While these are all pretty decent but,

• In Extra of the Wind (#MFTL) Marisa gets food stolen out of her hand by a crow.

• In Oriental Sacred Place Reimu gets surprised by snow falling on her.

• Chen gets scratched by normal cats in Bohemian Archive in Japanese Red. (Chen is also supposed to be capable of going FTE to normal humans)

• Characters also worry about travel time and silly shit like "it will get dark before we get home" when if they are relativistic they could do that in less than a second.

• In Imperishable Night it takes hours to travel from the start to the bamboo forest (Gensokyo is not very big). Though to muddle this a bit they were constantly fighting things along the way.

There are also some feats much lower than the speed of light but still on the higher end of the scale.

• In Legacy of a Lunatic Kingdom, the player character travels half way around the moon in presumably minutes to hours.

• In Cage in Lunatic Runagate, Yukari's familiar crosses across the Seas of Tranquility and Serenity on the moon over the course of a conversation.

• In Silent Sinner in Blue, Remilia presumably travels the moon in a few panels.

Touhou speed is not consistent. I do not think we can definitively call a character that is relying on a degree of power scaling to say they are FTL.

Though as a disclaimer I have not read all the mangas so their definitely could be feats I am missing.