Doesn't have to be a harem but I'm writing with that intent
Bonds au only onDanmachiside ex. Soulmate parent sibling bonds show up as names or symbols and colors red or gold is soulmate silver or blue is parent and bronze or green? as sibling black is not active and faded grey is passed bonds can't be rejected but it can take time for feelings to start
the gods can pick who they mate bond to with no more then 5 max though it has to be mutual consent for the chosen (ex of mate. bell x freya she can't charm him to except a mate bond.)( ex of sibling bond. Hestia and Loki)
Romantic ParringsfemharryxAisxRivieraxRyuux Rose x Asfi x Naaza xFreyaX Horn(Syr) xHephaestusxArtemisx Aphrodite x Athena x Prometheus x Tsubaki x Yamato xHaruhime
Bell x Hestia x Lilli
Parent Bondsfemharry and thanatos x Hades x Demeterx Erebus xIshtarx Dionysus x Takemikazuchi
Bell and Demeter
Sibling BondsfemharryandHestiaxLokix Finn xGaneshax Ares xHermesx Micah x Set x Wolf xOtterx Bete
You can add more or you can take some away bold and underlined are a must though

Takes place 2nd year summer after the Marge incident
Fem Harry(Alyssa it's a flower and Greek I checked)
Alyssa has traits from all houses but her dominate traits will be Slitherpuff
Good Gringotts

The next morning after Alyssa's meeting with the Minister she visits the goblins while there she gets a inheritance test that shows an ancestor from both parents on the Danmachi side from the Zeus and Hera familias(goblins only know this from said ancestors) her inheritance includes a library from Lilly (in the library must include a book with the blood adoption ritual ) and a way for her to go to the Danmachi world where she ends up with Zeus and her bonded brother Bell (they are both 12 but Alyssa is the older sister I just can't see her being the younger sibling to Bell even if you make him older by a few months or at all cause of the Dursleys) after she meets them she shows Zeus the inheritance test and ask about the gods here Zeus must admit who he is and train them both after he "passes" they both go to Orario now while they can both join Hestia I personally want Alyssa to be a artificer (inspired by gamerfiction harry potter and the artisan's path ) but with how I have her imagined I can not see her separate from Bell so maybe she can have a mentorship with Hephaestus through Hestia. Once they start dungeon diving Alyssa will be stronger then a regular adventurer because of not only her ancestors but the way her magic from the HP verse acts and flows through her whole body so it acts like reinforcement magic like in Fate. I don't actually have ideas for the story part except Ishtar changes her ways after meeting Alyssa