Not a ton of cards stand out to me in her kit, but there's a few obvious ones. Blood Cannon is a must-run, 4+ levels; it is both a massive amount of extra health and more resource. Most of all, without it, it feels like if I reach 750 hp I am just screwed- Blood Cannon makes health useful at anything 150+.

For cards I also like Blood Sense a lot, though I am unsure of how it holds up when not in high ELO. Sanguine Pact feels really good if your playstyle is compatible. Alternatively, Symbiotic Relationship/Waning Moon covers its own cost and still nets 20% increased healing.

As for the other cards, anything under Swarm feels meh at best. The cost is too high for those without anyway to cover them, so I don't think its worth. Of them Enriched Blood feels like the worst out of them. I think Wings of Terror will be my go-to for a mid-level card as the extra movement is essential to engage or disengage. Blood Sense at 1 on healing builds seems still worth honestly- all you need is .5 seconds for everyone to know their location. Gloomy Nook is a fine level 1 filler, as it gives you leeway to cast Death Wings if you are running Blood Cannon.

For talents, I currently prefer Cursed Accord. The damage loss feels bad but the extra healing turns her into a decent main healer. I like Maelstrom of Carnage in theory, but in practice I find it clunky- I don't really want Swarm on me since it doesn't heal me and also doesn't damage enemies meaningfully enough to be a get-off-me button. I think this card with continue improving as people better understand how to play into her healing, but for now I just prefer to put it further up. I haven't been able to try Murderous Intent but I do not find it particularly appealing. Enemies rarely group up like that, and 90 damage is hardly noticeable on most champs. I don't think it is worth running at all because the damage increase just doesn't really help it, but if you do run it Sharpened Slaughter is a must-have.

For items, I like veteran mostly. Being meatier is always nice, and from what I can tell it also increases Blood. Chronos is apparently ran a lot but I don't see how- the only cooldown that means anything can already be easily reduced. Haven is obviously helpful as it preserves resource and keeps you alive, especially as you dive head first into bad situations. The real dark horse is Moral Boost, which I think is super tasty on her. Getting ultimate back is extra healing and an escape option with the extra move on Death Wings.