There are several tricks and with Giada and Righteous valkyrie, this deck becomes more consistent with making it to mid to late game. Ive replaced exalted angel as that was my 3 slot mana creature with righteous valkyries. In my version3 build of this deck (I own 3 versions of this deck IRL) there are still 2 exalted angels.
Tricks you can do.
1 . 5 mana (karakas included) + Quick silver amulet + righteous valkyrie on the board + any legend creature- bounce the legendary eot of opponent and use amulet to put back down the creature to trigger life gain. You can do this repeatedly on opponents turn. karakas allows for some interesting shenanigans with Righteous valkyrie. Archangel Avacyn in particular since she makes all your creature indestructible, so you can keep re using her.
2. 5 mana (karakas included & phyrexian tower) + Quick silver amulet + Giada Font of hope - You can bounce legendaries to change the amount of counters they enter the battle field with.
3. Mutavault lands- These lands can count toward Giada Font of hope's counter additons for you angels. Think of it it as 1 mana to add more counters onto a creature as it enters play. They also count for lyra dawnbringers bonus effect of lifelink and 1+1. Righteous valkyrie also helps too. I've run mishra factories before and those work too with archangel avacyn's trigger, but the mutavaults are a better fit for the theme.
4. Baneslayer, Gisela, and lyra first strike triggers + righteous valkyrie - First strike can put you over the +7 starting life threshold to trigger the 2+2 bonus of righteous valkyrie. This is important because if your opponent is not aware you can end games quick or change the board state and begin winning.
5. 5 mana (karakas included) + Quick silver amulet + Shalai, Voice of plenty - you can bounce shalai back in response to something trying to kill her and you can replay her againg in response to threats on your creatures or yourself.
6. This is an old well known synergy with Land tax and Scroll rack hand/deck rearrangement and to a lesser degree sensei's divining top. I've won games with horrible hands because of scroll rack alone and having land tax out t1 helps put the pressure on opponent to gauge how much land to put out.
7. lands - Eiganjo castle - since we play alot of legendaries in the deck, eiganjo castle seemed like a good choice. Emeria for our plains count which includes mistveil plains. Though they are slow which is drawback and non basic, you can easily replace them with basic lands. I like recursion with this deck since we run land tax we can find our plains fast via enlighten tutor for land tax. Mistveil plains is there as a backup for anything we might want to reuse. fun thing is you can use mistveil plains in response to the nevinyrrals disk and place the disk back into the deck before it destroys your white permanents. Kor Haven is an early maze of ith land that cost mana but also produces mana since we have a high cmc. It has save the early games from getting nastly with goblin lackies if i mist a turn 3 drop. Phyrexian tower is there because opponents like to remove or gain control of creatures and its my answer to them targeting my creatures. I can also abuse it with angel of sanction's trigger and later use mistveil. emeria, or reya to get back the angel of sanctions while the opponent's non land permanent is permanently gone. I used to be able to sanc my mishra's factory for archangels avacyn's trigger but sine we use mutavualts now it doesnt work. There is also the ability to sac creatures to ramp as well but that is the least useable feature.
8. Sorcery- Balance - Its highly un- balanced and powerful. Helps me even the odds early game and even late game if things have gone bad. Wrath of god is standard for keep me alive mid game.
9. Instants- Swords to POWshares. Best white removal in game nuff said- Enlightend tutor doubles any enchantment (ob ring in sideboard) and artifact. It allows me to grab sol ring mana times and if im set, quicksilver amulet. Sometimes I'll even grab Platinum angel. You can also grab a board wipe with the disk too. So you have board wipe, creature, mana ramp or Bypass and finally deck maniplation with scroll rack / Top + land tax.
9. Creatures- Why some 1x and others 2x and 4x? So many Legendaries?
Legendaries are powerful and most of the time they get removed. If I play it smart I put down the Legendary i want the opponent to remove so i can play a Baneslayer or righteous Valkyrie. Those are the backbone of the deck i feel with a few support angels
Admonition angel ( which i might make 2x but its slow and land dependent) and Angel of Sanctions (used to be an o ring, but i like quicksilver this in as a response and also embalming potential)
The Archangel of tithes is a mixed bag. It helps with defense and also offense, being a 3/5 flier for 3 white and 1 colorless it fits the curve, the bad is 3 w can be hard with the amount of white mana in the deck.
Lyra is a no brainer as a lord and pressure builder. Shes basically the 5th baneslayer with positive effects.
Linvala is one the best 4cmc angels as she shuts down many things and draws aggro right away.
Shalai is actually a really good angel for also 4cmc like linvala and helps keep my baneslayers out on the field along with the righteous valkeries.
Giada is the newest angel and also one of the best for the deck. I only run 1 because i dont need her to make the deck work, but she helps early game and late game with the counters. Vigilance and flying make her great also and she immediately gets killed usually which means less removal later on for righteous and bane.
Akroma is an older fit which I might replace with sephara, but having haste and trample on an angel is very powerful and has helped me push through blocks, plus pro red and black, and vigilance along with flying & first strike is still a great card to run.
Archangel Avacyn is there for protection and her flash ability is nice for annoying opponents. If there is 6 mana including karakas, i can pull some annoying shennanigans with her too.
Gisela - A mini bane slayer but it draws removal early on and makes the opponent think im running brusela. Its an okay 4 slot cmc but lifelike and firstrike on top of flying isnt bad, plus i can use eiganjo castle or karakas to save.
Platinum angel - Very annoying card if they cant remove or deal with this. I've won games I have no business winning because of this 1 card. Saved my teammate in 2hg once for 40 minutes to a well deserved win. Can tutor with enlightened tutor
Reya Dawnbringer - Lyra's ancestor and shes a bit outdated but I wanted recursion. Strictly worse compare to sheholdred in a non angel setting, but this is an angel deck. Can save her with karakas and/or eiganjo castle. There are synergies with phyrexian tower and her. Sac angel of sanctions or admonition angel while their triggers are on the stack with phyrexian tower and bring them back next upkeep to do it all over again. You can also trigger life gain with righteous valkyrie this way too and reset counters on angels with giada's ability.
Iona, Shield of Emeria - Last but not least. If the stars align right and all is well and you win the lottery, you can lock out an opponent turn 2 with mana vault, sol ring, iona and quicksilver amulet along with 3 lands in opening hand. Funny thing is , this happend when I was playing my Friend Andy L. He was playing mono red goblins and had a goblin lackey out on t1 and my turn 2 i dropped iona and named red. He was a champ and played it to the end. This was about 11 years ago, so dont count on it happening much.
Sideboard - Make it what you want. i wanted various things which i'll explain later, but for now im tired of typing.