In the trial version of Wily Beast and Weakest Creature, spellcards 29, 30, 31 and 32 would not unlock in the spellcard menu even if you encountered them in-game. They would still be displayed as “? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?”. Moreover, they seem to be tied to spellcards 17, 18, 19 and 20.
Let’s assume you have a fresh scorefile. Starting a regular gameplay, you reach Urumi’s last spellcard 鬼符「デーモンシージ」Oni Sign "Demon Siege" (Easy/Normal) or 鬼符「ハングリーデーモンシージ」Oni Sign "Hungry Demon Siege" (Hard/Lunatic). The history in the top right corner shows 00/01.
You go past that, advance in the game until you reach Kutaka’s last spellcard 鬼符「鬼渡の試練」Oni Sign "Trial of Oniwatari" (Easy/Normal) or 鬼符「鬼渡の上級試煉」Oni Sign "High-Level Tribulation of Oniwatari" (Hard/Lunatic) and you notice that in the top right corner it says either 01/02 (if you captured Urumi’s last spell) or 00/02 (if you failed Urumi’s last spell).
That would be odd since it was the first time you saw Kutaka’s last spell, why would it display /02. Going to the spellcard menu you will notice that Kutaka’s last spell is marked as ? ? ?, but instead of Urumi’s last spell, the name of Kutaka’s last spell is displayed.
To make Urumi’s last spell name appear in the spellcard menu, you have to play again, but quit before reaching Kutaka’s last spell. If you see Kutaka’s last spell again, then again her spellcard name will show up instead of Urumi’s.
However, in the spellcard menu, spells 17, 18, 19, 20 will have an increased spell history (it counts both Urumi’s and Kutaka’s spell into that).
Fortunately, this seems to have been fixed in the full version. I posted below two videos for reference.
ver. 1.00b (not glitchy) - it was fixed since ver. 1.00a