Which of the free chars are worth investing on?

i need to unlock 10 mana nodes for one of the jumpstart quests, right now i only have the free units and i only have 2 days left. who should i invest on?

Euden is great and has mana spiral. Elly is a great buffer.

Id work on the prince since he gives player exp when mana maxed 41-50

You have a choice with either Euden, or Elisanne. Both of them are extremely great characters, and are still usable to this day in end-game content.

Go for Euden for an ATK flame-attuned character. Thanks to his new spiral he’s been heavily buffed.

Go for Elisanne for an all-around buffer. Don’t underestimate that sweet 20% strength buff. It will heavily help in timed-content like Mercurial Gauntlet. With the right actions and equipment, that buff will be near permanent.