Thanks for the feedback! The game being quite RNG dependent is a design choice as while it gets some lows, it makes the highs even sweeter. Same with multiple lives.
You can influence that RNG as it's an ongoing trade off on what to sell vs keep based on how far ahead you are on the quest.
Do you sell some spells you need later to open an advanced or expert pack for the chance at powerful cards you need now.
Greatly appreciate you taking the time to leave the feedback!