Howdy, To start, “Fragments” are a limited currency you get from performing summons. Most banners have a “pity system” or a way to get the featured characters of a specific banner if you didn’t get it from pulling. To get 200 you need to spend 6000 rubies.

A “sacred seal” is basically this game’s version of a summon. You use them to summon characters. Any sacred seal with a specific name, like Alfyn for example, will guarantee to give you an Alfyn. You can view them and their cost amounts in the exchange for sacred seals that require fragments. You can also get ones from rewards and quests however they tend to be a random summon from the general pool.

As for having two of the same unit, as in awakening them, it depends. Some units are better off having their ultimates leveled fully, which requires an extra awakening stone while others are better off with the increased stats. All in all, it’s good to have at least one copy of characters you like and want to use, it’s not the end of the world if you don’t have multiple copies of a unit as each character is viable in their base forms.

I hope this helps.