This is a counterpart article to the Grixis Delver. By swapping the black cards for white cards but keeping the other concepts of the deck much the same you end up with a list rather like this. It is one of the best decks in the cube, it is slightly softer to control and mass removal than the black versions but it is stronger against midrange and aggro matchups. Overall I would say that the Grixis build has more raw power but the Jeskai version is more robust and reliable. Jeskai has more depth and redundancy in the card pool than Grixis making it easier and safer to draft. It also leans less heavily on any given card or card type which is kind of just another way to say it is more reliable and robust.
Another somewhat fascinating attribute of the Jeskai prowess deck is that you can morph it one card at a time from an aggro deck into a control one without ever passing a weak incarnation of the deck. It is a bit like those word puzzles where you have to change one letter at a time in a series of changes that lead to a final word, each step of the way however must spell another word. This should demonstrate why it is a pretty safe deck to draft. The further away from an aggro deck you go the less the deck is about prowess and so I have given an example list that is reasonably heavily on the aggressive end of the spectrum. The more aggressive you go the less blue you will typically play but the inclusion of the blue does still push it significantly past an aggro Boros deck in terms of power and versatility.
Path to Exile
Mother of Runes
Kytheon, Hero of Akros
Figure of Destiny
Seeker of the Way
Abbot of Keral Keep
Jace, Vryns' Prodigy
Fire / Ice
Raise the Alarm
Stoke the Flames
Sea Chrome Coast
Other strong contenders
Jace, the Mind Sculptor
Geist of Saint Traft
Delver of Secrets
Force of Will
4 mana Chandra's
The list has more threats and more removal while it has less card draw and quality. You need the draw and quality less because the deck is more consistent and redundant. This frees up space to further perpetuate this effect. You only play one Dig or Cruise in this list typically because it is not so painful when you don't see one and it is more damaging should you see both early. You are less focused on delve so you need less looting effects to power it. Although still good in the deck you don't want to be going over board on looting. Grim Lavamancer is basically a delve card and this list supports him far better than the Grixis one because it is supporting less other delve cards and the mechanic suffers from diminishing returns.
Jeskai Ascendancy is the Thoughtscour of this deck in that it is the only card I do not have in the main drafting cube that is in the list. While absurdly powerful it is narrow beyond belief. This is one of the few decks it is good in and basically the only one you can build using cards in my main cube. It doesn't do much on its own but should you have any sort of board then the game is basically over when you play it. Powerful though it is it probably makes the deck less consistent, you don't need it to have a great deck. You can throw in other build around cards like Opposition too and while they will win plenty of games for you they are much more work to sensibly include and don't make the deck that much noticeably better. It turns out this deck is just so good already you don't need to bother which such things. I may well look to cut the Raise the Alarm from this list without the Ascendancy or other global pump in it.
Monastery Mentor is even more of a silly solo game ender. He is slow to do much work but if you leave him in play too long then you will lose to him. This deck does not struggle at all with casting several spells a turn, it can easily do it just off the top, it can do it at end of turn. You can feel safe with just a poxy Mentor in play when you pass, have them cast two or more things at end of turn, untap and cast a bunch more non-creatures and just kill you.
As ever these decks pose the counterspell question. The curve is more consistent and usually lower with Jeskai prowess than it is with Grixis delve and so I prefer to go with Abbot of Keral Keep and forego them entirely. When I have spells in my hand I want to cast them so that I can trigger my prowess! I also don't want to exclude one of the best prowess cards going just to play permission. That all being said, as aggro decks go, permission is better in this deck than most and only gets better the more you move towards midrange. Obviously the best ones to start out with are the cheap and free ones with room openening up for more standard ones as you become less aggro.
Seeker of the Way is a bit of a filler card. You don't really need the lifegain and although he has prowess he doesn't actually offer that much to the deck. He is not a game ender in the same way a lot of your dorks can be. He does however give a great tempo injection while being scary to block or burn should you have mana up and cards in hand.
This deck has less two for ones than the Grixis list but it comfortably makes up for that with more and better tempo cards and way more dangerous games ending cheap threats. Comparing the two lists is somewhat irrelevant anyhow, the point is that they are the best decks in cube at present and are very similar to each other. It will be rare for a table to have both decks being contructed and when that is the case both will be much weaker from having to share the Izzet lands and cards. Certainly it can be done, the mana is more of an issue than the card pool. At least one would have to end up with blue as the splash and no double blue casting costs. This list here is almost at the stage where the blue is a splash, it has no doubles and fewest blue mana requirements however it has a little too much one drop card quality in blue to be a real splash.
Both decks are very fun and very powerful. They let you use lots of cheap and powerful spells. They let you have tempo and card advantage all at once. They are full of choices and options and really let you play magic. They are also comprised almost entirely from cards currently in standard plus a dash of some legacy staples.