Since it is really fascinating how you can essentially build up your units with whatever valid skills you obtain in Seer's Snare however you like, wouldn't it be really cool if you could actually get these skills permanently for your units to learn and use outside of the event?

In my honest opinion, Seer's Snare is one of the most unique and creative events that FEH has ever done; it feels like playing a dungeon crawler or a roguelike in which you guide your team through a series of dangerous challenges and pick up useful loot along the way for each challenge you overcome. There's even event-exclusive currency (Rift Vessels) that you earn as you progress, which you can use at shop zones (Vanir Seals) to purchase skills to equip and build your units with. It's really fun because not only does it provide plenty of challenge for the player, but also it grants them a lot of room to experiment with whatever they've got while challenging them to make important decisions on where to go next. It is pretty cool how you can make your units really overpowered with all those top-tier skills you can obtain throughout the whole journey. So why not allow us the option to actually retain them after Seer's Snare is over?

They could introduce a new kind of rare resource which would allow us to permanently add skills obtained in Seer's Snare to the skillsets of our desired units, which can be bought in the Celestial Stone Shop. They already allowed us to purchase Forma Souls with Celestial Stones, allowing F2P players the option of building units with really powerful, max-investment level skillsets in Hall of Forms to obtain later. Therefore, it doesn't seem to be too gamebreaking if we can spend our Celestial Stones to grant the really powerful skills we got in Seer's Snare to our units to build them. Besides, this kind of option can also incentivize players to use some of their more favored (if albeit weaker) units in Seer's Snare by granting them the opportunity to significantly improve them afterwards. Any thoughts on this idea?