This crash is an interesting one. Managed to grab a prismatic shard on a run with a modded character called the Cursed. Level Up started showing up, and the first few times I picked it, everything went fine. Then I picked a card from the animator mod and it crashed. Crash log below.

03:08:36.986 DEBUG basemod.BaseMod> Transitioning room to floor #32
03:08:37.007 INFO helpers.File> Successfully saved file=F:\SteamLibrary\steamapps\common\SlayTheSpire\preferences\THE_CURSED
03:08:37.007 INFO helpers.FileSaver> Dequeue: qsize=0 file=saves\THE_CURSED.autosave
03:08:37.010 INFO helpers.File> Attempting to save file=F:\SteamLibrary\steamapps\common\SlayTheSpire\saves\THE_CURSED.autosave
03:08:37.037 INFO helpers.File> Successfully saved file=F:\SteamLibrary\steamapps\common\SlayTheSpire\saves\THE_CURSED.autosave
03:08:37.695 INFO basemod.BaseMod> publishPostCampfire
03:08:37.695 INFO infinitespire.InfiniteSpire> Setting Reopen to false
03:08:37.697 INFO infinitespire.InfiniteSpire> isStuck: false
03:08:38.180 INFO elementalist_mod.ElementalistMod> ElemLog: ElementalistLevelUpEffect.getLevelUpPerkChoices()
03:08:38.180 INFO elementalist_mod.ElementalistMod> ElemLog: reward cards: 8
03:08:38.183 INFO rooms.RestRoom> This should only be called by DreamCatcher!
03:08:38.185 INFO rooms.RestRoom> This should only be called by DreamCatcher!
03:08:38.188 INFO rooms.RestRoom> This should only be called by DreamCatcher!
03:08:38.193 INFO rooms.RestRoom> This should only be called by DreamCatcher!
03:08:38.196 INFO rooms.RestRoom> This should only be called by DreamCatcher!
03:08:38.198 INFO rooms.RestRoom> This should only be called by DreamCatcher!
03:08:38.200 INFO rooms.RestRoom> This should only be called by DreamCatcher!
03:08:38.202 INFO rooms.RestRoom> This should only be called by DreamCatcher!
03:08:38.205 INFO rooms.RestRoom> This should only be called by DreamCatcher!
Exception: java.lang.NullPointerException
03:09:00.952 ERROR core.CardCrawlGame> Exception caught
java.lang.NullPointerException: null
at com.megacrit.cardcrawl.cards.AbstractCard.applyPowers(AbstractCard.java:2943) ~[?:?]
at elementalist_mod.ElementalistLevelUpEffect.update(ElementalistLevelUpEffect.java:77) ~[ElementalistMod.jar:?]
at com.megacrit.cardcrawl.dungeons.AbstractDungeon.update(AbstractDungeon.java:2640) ~[?:?]
at com.megacrit.cardcrawl.core.CardCrawlGame.update(CardCrawlGame.java:878) ~[?:?]
at com.megacrit.cardcrawl.core.CardCrawlGame.render(CardCrawlGame.java:429) [?:?]
at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:225) [?:?]
at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:126) [desktop-1.0.jar:?]
Controllers: removed manager for application, 0 managers active
Game closed.