Hades isn't your regular roguelite, and all of its progression elements are a testament of this. Building relationships both inside and outside the House

How to Obtain Nectar and Ambrosia
These two items are a rarity of sorts in the underworld, historically portrayed as forbidden beverages. Everyone loves them, which makes them the perfect gift to strength your relationships with your relatives. Doing so will unlock different things, such as Keepsakes, as well as new narrative events and side stories.
Nectar can be obtained during runs most of the time. You’ll often see them as rewards before entering a room, pictured as this orange flask that looks like a potion. You just have to choose that path, take all Shades down, and grab it as a reward. At times, some Boons will give them as reward, as well as other bonuses for your current run the next time you grab another bottle. Lastly, you can also trade items for it (5x Chthonic Keys) in the house lounge.
Ambrosia is a bit more complicated. It will appear as a limited item in the trader once in a while, so always double check for it. But, it’s usually granted as a reward for beating bosses. Thankfully by the time you become able to use Ambrosia, you’re gonna have more than a few ready to gift away, but keep this in mind for future runs – increasing the Heat in the Pact of Punishment to renew your weapons’ rewards will guarantee more of this item.
How to Gift Nectar and Ambrosia
Once you get your hands on Nectar in Hades, every time you approach a key character (either underworld NPCs, people in the House of Hades, or God Boons) you’ll see the regular dialogue button prompt, as well as a new prompt with the drink’s icon. Pressing it first won’t skip the dialogue so it’s always best to do so.
If it’s your first time, chances are Zagreus will obtain a new Keepsake in return. This will increase your relationship with said character, signalized as a heart. If you check the index, it will showcase you how many hearts you have obtained with the character thus far.
In order to keep on deepening that relationship, sometimes you’ll have to talk to them for a couple of times (which will appear in the description below inside their index), but if it says that you need to deepen your relationship with them, that means they will want Nectar.
Once you have reached a certain point with a number of characters, they will start taking Ambrosia instead of Nectar. A good thumb rule is to always have one of each before you start interacting with characters. If you see the icon, it’s because you can advance your relationship with them.