Knights package + Angels package midrange deck splashing green for Find // Finality. The "Find" half helps us grind and functions as card draw while the "Finality" half can clear the board in a pinch while keeping our favorite X/3 angel alive.

Knights Package (lower curve): Knight of Grace and Knight of Malice turn on each other, get turned on by Seraph of the Scales, and are powered up by History of Benalia. The fact these knights dodge W/B removal is quite relevant as well, as it essentially only guarantees that your opponent's red removal will always work. Previously I have seen people run Adanto Vanguards, Tithe Takers, and Tocatli Honor Guards (which you might still want in the side board!) while I personally have enjoyed Seekers' Squire as a two-drop. Any and all of these are viable two-drops in an angels deck. However, the potential explosiveness of the knights are more likely to sneak in some damage from underneath slow decks and are otherwise just as good vs. aggro/board control match-ups. With all our green sources you could also consider Merfolk Branchwalkers or Growth-Chamber Guardians, though at a certain point you might as well just play a Golgari deck...

Angel Package (higher curve): The core angels package is Resplendent Angel, Seraph of the Scales, and Lyra Dawnbringer. I also like to mainboard Shalai, Voice of Plenty as we can actually make use of her activated ability to grind out and she can seriously annoy some decks, plus buffing up first striking knights is no joke. She is easily replaced by more relevant cards in the sideboard as needed. Resplendent Angel is of particular consideration as a win condition: if ever you have another viable play in the early turns such as History of Benalia or a knight +tapped land, I would suggest not throwing this angel to the mercy of the opponent's removal if you can help it. It also makes an incredible top-deck in the late game and an excellent target for Find // Finality or Memorial to Folly to recur. Meanwhile, Seraph of the Scales' ability to play offense/defense with vigilance is helpful in combat-centric match-ups and her deathtouch allows her to answer any threat. Be sure to activate the vigilance before the combat step, and always get in those mad style points for activating her ability when they hit her with removal.

Removal package: Consecrate // Consume is a hedge vs. big creature decks that isn't dead vs. control as it can be cycled (and can even deal with Arclight Phoenix/Rekindling Phoenix), Mortify can very importantly hit enchantments, and Vraska's Contempt hits planeswalkers and exiles. These are fine-tuned to be more efficient vs. the matchup in the sideboard. Removal is meta dependant, adjust as needed.

Sideboard: Most of the sideboard is removal, namely: Moment of Craving, Cast Down, Assassin's Trophy, and The Eldest Reborn. Additionally, Vivien Reid comes in for grindy matchups where we don't feel we can aggro the opponent out (such as against other midrange decks), while Duress comes in vs. control, usually in replacement of some removal. There's an extra land in the sideboard in the event we side into more big spells (such as by adding in vivien's AND eldest reborns.) I generally feel I don't need a sweeper as we can hold our own in a board stall and always have access to Find // Finality in the maindeck. Against white aggro decks we can hopefully defend with our first strikers while using spot removal and racing over our opponent's head with lifelinking angels. Cry of the Carnarium can be considered, replacing either Cast Downs or Moment of Cravings if go-wide decks become a problem.

Easy cards to swap out are:

Aggro:
Cut 1 Mortify and 1 Find // Finality for 2 Moment of Craving;
Cut 2 Mortify for 2 Cast Down vs. aggro without enchantments;
Cut 3 Find // Finality and 1 Mortify for 2 Cast Down and 2 Moment of Craving when you just need to survive;
I sometimes keep in Consecrate // Consume and Vraska's Contempt even if they are expensive for the lifegain vs. red decks.
However, vs. swarm aggro decks replace 2 Consecrate // Consume with 2 Cast Down while possibly boarding Moment of Cravings without cutting Find // Finality. When facing a white deck that is really likes its enchantments, don't cut Mortify as much and possibly cut your top end a bit.

Midrange:
Cut 2 Consecrate // Consume for 2 The Eldest Reborn vs. decks with a few big threats where you don't care about lifetotal;
Cut 2 Consecrate // Consume for 2 Assassin's Trophy for when you seriously need to kill planeswalkers;
Bring in Vivien Reids (and possibly the extra land) vs. midrange decks by boarding out 1-2 Lyra Dawnbringers, 0-1 Seraph of the Scales, 0-2 Consecrate // Consume, and/or 0-2 Shalai, Voice of Plenty depending on how much removal they have vs. how much removal you need. Optionally you can add in 2 The Eldest Reborn, which necessitates another land.
Generally you can trim Consecrate // Consumes/Vraska's Contempts/Mortifys for Cast Downs/Assassin's Trophys for matchups where removal needs to be as efficient as possible but you don't need as much utility.
Feel free to cut Find // Finalitys for extra removal if you don't need to grind through your opponents removal as much, such as vs. a Simic Climb deck.

Control:
These are a bit more complicated, as you can have up to 10 cards you might want to bring in with Duress, Vivien Reid, Assassin's Trophy, and The Eldest Reborn. In order to board these in, consider dropping any of 2 Consecrate // Consume, 0-3 Mortify, 0-2 Shalai, Voice of Plenty if they are light on spot removal and rely on sweepers and counters, 0-1 Seraph of the Scales and 1-2 Lyra Dawnbringer if you need to go lower down the curve with your creatures.

Landbase: We run 25 lands as we only *need* to hit 3 lands guaranteed to function and prefer to hit 4 on turn 4. We can live if we don't slam our one 5-drop on turn 5. Meanwhile, we do have a 6-mana spell in Find // Finality and 6-mana dumps in Resplendent Angel and Shalai, Voice of Plenty in the event that we have mana to spare or flood out. There's 18 white sources, 15 black sources, and 13 green sources. This is enough to hit 2 white on turn 3, 2 black on turns 4/5, and 2 green on turns 5/6. There's an extra BG dual land in the side board to help ensure we can hit Vraska's Contempt on 4 and Vivien Reid on 5.

This beats up on aggro pretty hard but wants to sideboard vs. control. As far as midrange decks go, this definitely has issues vs. the Sultai Krasis midrange decks as their ability to grind out value is unmatched. Our creatures do, however, have much more explosive potential - we are more interested in beating the opponent to death than we are grinding out infinite value.

I'm always trying to uncover the best angels deck!