I'm not really a big fan of DIONA but I'll take whatever FREE STUFF I can get in a game where leveling up a character's constellation will be either so expensive or would take at least months to do so (especially for players who are not topping up on the game)
Anyways, yeah the current ongoing event on Genshin Impact gives one this cute little fella right here.
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All one needs to do is accumulate 1000 (I forgot what it was called XD), send an invitation to DIONA as you can see below and that's it! FREE DIONA!
One can accumulate those from the ongoing "Energy Amplifier Invitation" event.
There are 3 Acts and 3 Missions per ACT which gives one those tokens needed to get that FREE DIONA. One can also use these tokens to redeem for items on the event shop which currently has 5 60 PRIMOGEMS and 1 CROWN which is only a limited event character material level up ingredient so this one should be everyone's priority!!!!
As for how the game event works, well it is kinda straight forward DEFEAT ALL ENEMIES surrounding the Irminsul Fruit Fragment and that's it! XD