This is my approach on a pyromancer ascension, i choose to ran a creatureless deck because of the heavy sorcery\instant commitment ascension demands and because could not find any creature that sinergizes well with ascention. Choose to ran WRG for the following resons:
WHITE:
*It helps us survive until ascention is online. (life gain).
* It help us to dig for answers (card draw)
RED ( the color of our win condition)
*Ascension is red, so we must run red in the deck.
*If we plan to win through instant/sorceries direct damage is a solid win condition.
*Acts as removal at all stages of the game.
GREEN:
*To recycle spells at critical points for card advantage.
*To bring back ascention if destroyed\discarded.
*To accelerate and dig for business spells.
The aim of the deck is to cast an early ascention and then generate huge amounts of card advantage or tempo (2x1s ) once it becomes active, then proced to win by burning our opponent . Our main focus should be to prioritize survival at all stages of the game, remember we can always bring something back with regrowth so we dont fall behind ( we just need a single spell once everything is set up, so dont be afraid to spend your burn on every creature if that means we can keep drawing cards from cache).
CARD CHOICES:
PYROMANCER ASCENTION: This is our winning condition, we need it early so we can generate card advantage ( remember we dont run creatures, so every advantage we get will be in the form of extra cards or life gain, ascention is there to ensure we can 2x1s with every spell) and we need it late so we can finish our opponent with ease ( we can still win without ascention but it will require recursion and rigurous resource management).
BOROS CHARM: This card does everything we need it to do. it takes an awesome 1/5 of our oponents life points, and it provides protection for our ascention against enchantment hate and can foil land destruction. The only drawback is that it does not target creatures.
INCREASING VENGEANCE: early-mid game this will be helpful killing large creatures if our ascension is down and we dont have enough burning , dont be afraid to use it early if you have to, his flash back bonus can make you win an apparently lost game (assumming you have an online ascention you can turn a topdecked captured sunlight into a whooping 24 life + random spell casted twice (helix,charm, cache, or regrowth) or a helix into 18 dmg and 18 life gain, or a charm into 24 dmg to the face.
LIGHTNING HELIX: This will be our early game removal, its main role is to keep our life at a healthy level.
NOXIUS REVIVAL: It is there just to make sure we draw what we need next turn ( see the increasing vengeance scenario as an example).
WARLEADERS HELIX: Same as lightning helix but with a wider effect.
CAPTURED SUNLIGHT: I love this card, life is always welcome specially if it comes with a free spell attached (even if it is somewhat random), remember we need to have lots of sorceries and instants in the grave to proc ascention more easily, and C. Sunlight will always net 2 cards to the grave. You will get 7-8 life most of the time and either free dmg, free cards, or a card back from your graveyard.
EXPLORE: This will help us to acelerate and dig for ascention early game and will become one of the drawing spells midgame so we dont run out of gas once ascention is online.
FAITHLESS LOOTING: Our main filtering engine, it will hel us find ascention or land card if we have missed a drop early, as well as filling our graveyard with the spells we need to proc ascension. Use it late game to turn your land draws into business spells.
RED SUN ZENITH: This is our primary winning condition once we have enough mana and an active ascention. Dont be afraid to use it early as removal, you will eventually draw it back.
REGROWTH: Its main purpose is to ensure we have something to do at all stages of the game, use it early to fetch back helix if you need removal, or use it to grab captured sunlight\survival cache if you are stuck with no relevant spells to play( you will get a free spell or a free draw most of the time ) or low on life. And most importantly use it to grab a zenith or ascention if needed.
Note that this is one of the most ridiculous spells to cast once ascention is online since it will open all kind of plays for a mere 1G.
Feel free to switch this for recollect or reborn hope if you dont have any(The deck was originally oriented to a reborn hope version, thats why it has lots of multicolor cards).
SURVIVAL CACHE: The purpose of this card is to keep us at a healthy life total, and, due large amount of life gain cards in the deck will assure we can get the card draw most of the time. remember this is a :draw 2 cards, gain 4 life spell almost every time we cast it and that doubles with an ascention in play, so it is never a bad card to topdeck (Only time we do not want to draw this is when opponent is 5 or more life points above us and has pressure on the board, but even then those extra life points we will get from it may guarantee we get to life for another turn and maybe draw a bbusiness spell in time).