The A-Z of slay the spire (a puzzle)

If you've never played the A-Z game you pick a topic (like slay the spire) and go through the alphabet naming an item (if you can) for each letter in turn. So (and I'm giving something away here) you might go apotheosis then ball lighting and so on)

Well heres the thing....

In all the slay the spire cards, there are THREE letters of the alphabet that are not represented in a card name

What are the three letters of the alphabet with no corresponding slay the spire card?

Looking this stuff up online will result in a shark being dropped on your house. Not a happy shark either. It will be disgruntled. So don't do that.