I always thought that, with the ever-changing meta, that characters should have a form of 'Adornment' system like how Ribbons exist in Pokémon to detail things that the earlier generations once had previously but newer ones no longer do. I feel this would be a neat addition with no other purposes other than... maybe a few tasks dedicated to it. It just feels like something that'd be fitting, especially with things like banner reruns, fes units being demoted, and so-on. This is a quick write-up of what I think could be done for this concept if it gets off the ground.
First: Where to find them. I feel these should appear under the Switch Effect section of the menu and next to your profile if the favorite you have equipped has any. They should use original graphics as well (not depicted in the mockup). Tapping on them should also detail specifics- maybe the date obtained or more specific information on the adornment itself.
Second: What to give out adornments for. These can be for a multitude of things, but here are my thoughts for various ones that'd work for most units.
- First Come, First Serve - The unit was obtained in it's first banner.
- Chance Meeting - The unit was obtained at a higher rarity than what it currently is.
❤️ - Friendship - The unit has, at some stage, has reached Pink Heart status.
⭐ - Devoted Challenger - The unit has been involved in the completion of an EX/Conflux Stage. (The description of this also lists off every EX/Conflux Stage it has completed.)
💍 - Rejuvenation - The unit has entered Fantasy Rebirth.
💎 - Reborn - The unit has completed every tier that is part of Fantasy Rebirth. (Anima, Costume)
💎 2️⃣ - Twice Reborn - The unit has completed every tier that is part of Fantasy Rebirth II. (Skill Tree completed)
These are what I thought of originally, but more suggestions for these are obviously welcome. However, I will continue onto related tasks next.