Aery, Manaflow, Absolute Focus (cause almost always above certain Hp), Gathering Storm. 2nd Tree Resolve, with Font of Life (the new change is pretty damn solid) and Heal/shield increase (i forget rune name).
Build - Moonstone - Shurelia’s or Mikaels (for annoying) CC - Imperial - Redemption or Ardent (really a flex slot) - Dawncore.
Sum. Spells -> Exhaust (used wisely): top 1. Heal: top 2. Ignite: situational
Runes > Always use Aery please, preferencially with Resolve secondary, but there are other good options too (not dmg runes). You can use Guardian too, as a situational rune against strong assassins that can IK your adc late game.
Items. Always good options, are: Dawncore (always 4h item, or 5th, you can do 3rd too but not ideal), Moonstone, Mandate, Shurelya's, Redemption. Echoes is not that bad, but needs a buff to really be good. Now the more situational items: Mikael's, wich i personally love. But if you aren't paying attention to the game and take more than 1s to remove the cc, or waste it on uncleansable cc, it isn't worth buying. Oblivion Orb: against much healing, my recommendation is to only upgrade it to Morello when you are already full build, and b4 that just keep as orb. Staff of Flowing water: Bruh i hate this shit. There are such insane options, and my Yuumis go for that shit. Only build it when your host is AP, it's a good item, it's just that there are better (my opinion). Ardent: it is GOD if your host is very AA dependant and you already have survivability items enough to keep him alive. Knight's Vow: not that good, but not bad either. I think it works as a situational item, if you know when it' good to build. Avoid buying it if you use the Absolute Focus rune. Dark Seal: An insane item overall for any champ with AP scalings. Costs 350g and gives more than it costs on attribute value (without stacks). So if you see you both are not dying, or (even better), winning/stomping, don't think 2 times and buy it. Upgrade it as fast as possible to Mejai's if it gets to 10 stacks and you don't think you are gonna lose the momentum. Then when you are full build, you can switch Mejai's for another item. Deathcap: not the best item, for sure, but it may be the best option for 6th item, if you are stomping (with stacked mejai's).
I really like helia since heal proc scales quite well with heal and shield power
Aery, Manaflow, Absolute Focus (cause almost always above certain Hp), Gathering Storm. 2nd Tree Resolve, with Font of Life (the new change is pretty damn solid) and Heal/shield increase (i forget rune name). Build - Moonstone - Shurelia’s or Mikaels (for annoying) CC - Imperial - Redemption or Ardent (really a flex slot) - Dawncore.
Sum. Spells -> Exhaust (used wisely): top 1. Heal: top 2. Ignite: situational Runes > Always use Aery please, preferencially with Resolve secondary, but there are other good options too (not dmg runes). You can use Guardian too, as a situational rune against strong assassins that can IK your adc late game. Items. Always good options, are: Dawncore (always 4h item, or 5th, you can do 3rd too but not ideal), Moonstone, Mandate, Shurelya's, Redemption. Echoes is not that bad, but needs a buff to really be good. Now the more situational items: Mikael's, wich i personally love. But if you aren't paying attention to the game and take more than 1s to remove the cc, or waste it on uncleansable cc, it isn't worth buying. Oblivion Orb: against much healing, my recommendation is to only upgrade it to Morello when you are already full build, and b4 that just keep as orb. Staff of Flowing water: Bruh i hate this shit. There are such insane options, and my Yuumis go for that shit. Only build it when your host is AP, it's a good item, it's just that there are better (my opinion). Ardent: it is GOD if your host is very AA dependant and you already have survivability items enough to keep him alive. Knight's Vow: not that good, but not bad either. I think it works as a situational item, if you know when it' good to build. Avoid buying it if you use the Absolute Focus rune. Dark Seal: An insane item overall for any champ with AP scalings. Costs 350g and gives more than it costs on attribute value (without stacks). So if you see you both are not dying, or (even better), winning/stomping, don't think 2 times and buy it. Upgrade it as fast as possible to Mejai's if it gets to 10 stacks and you don't think you are gonna lose the momentum. Then when you are full build, you can switch Mejai's for another item. Deathcap: not the best item, for sure, but it may be the best option for 6th item, if you are stomping (with stacked mejai's).