To all you mighty warriors!

How you use your diamonds is a very important issue. Early on, it's wise to prioritize gacha for securing characters or the 'Witch's Letter' needed for evolution. Utilizing fast battles during double event days on specific weekdays is also efficient, Hou!

If you're thinking about character breakthroughs, I recommend saving up until the character you want comes out. I'm currently saving for Sui Fear, who is scheduled to be released soon. Depending on whether there are hidden quests, etc., I think it's better to prioritize using friend summons (please fill your friend slots to the max) and platinum tickets over using gems for character banners. There's also something called a weapon banner that will come out later... (If there are hidden quests or time-limited events, I think it's best to rush through the main story.)

I don't know the exact situation, but... For the Platinum Gacha, only use tickets (don't spend diamonds). If you want a pickup character, it's better to pull from the Destiny Gacha. There are so many things you'll want to spend diamonds on, like Letter Gifts, Shards, character pulls, equipment gacha, etc., that you won't have enough diamonds if you don't focus on something 😭 So, it really depends on how you want to proceed. If you want to clear quests and towers as quickly as possible, you'll use diamonds for Letter Gifts to collect R items and for gacha equipment for your main attacker (you generally won't pull for pickup characters). If you're okay with progressing slowly and getting equipment over time, it's better to save your diamonds.