Well it is technically possible by summoning ra the regular way and cards that special summon like a hero emerges, burst rebirth or symbols of duty. But of course this is not meant to use against somewhat decent opponents but more for duel quiz and 🔥s and giggles
I still think she should have been a Fusion Monster, since she is the combined form of all 3 Egyptian Gods...
If she does ever come to Duel Links, it should be via a Skill that you can ONLY use in an event that's based on Dawn of the Duel, against Zorc. You don't unlock it or anything, it's only available during that specific duel.
My idea was that it specifically Special Summons the 3 Gods from the GY, then fuses them like it did in the anime, and can only be activated if the player has My True Name in their hand.
At the beginning of the duel add 1 "Horakhty" to your deck.
Activate this effect if you have normal summoned a "Divine Beast" monster during this duel: Tribute 1 "Slifer", 1 "Obelisk" and 1 "Ra" from your hand, field or GY; special summon 1 "Horakhty" from your hand.