The art of serenity - speak softly and carry a big stick

I'm not sure I could make something I could win with. I just really like the mechanics and I kind of want to build around them to see what I can do with them.

Indeed - I think it's like Extort and, to a certain extent, Evolve. All of them are mechanics that look really promising - and in the right shell can be game winning - but you almost never saw an extort deck that just wanted to sit back and use extort as a win condition, nor an evolve deck that tried to lever the mechanic with all it's creatures.

More usually you saw 1-4 cards with that ability on it which saw play in shells that levered them for all they were worth. Prowess creaturs have made their mark in mono-red aggro and in W/x decks as efficient creatures, Extort creatures appeared in the aristocrats build from a while ago and also sometimes in Orzhov Humans whilst Evolve really worked in the devotion decks at the start of Theros with Cloudfin Raptor and Experiement one doing a lot of work.

I think that I could make a 'good' Jeskai deck - one that would be fun to play and wouldn't be too embarrassing - but in order to make something that could consistently win games I suspect that at the moment I'd have to drop down to 2 colors - probably W/R on preference but also likely W/U would work well - and probably run almost half of the 'other creatures' as non-prowess.

What I feel I might be doing is actually selecting a suitable Tiny Leader or even EDH commander and making a jeskai deck around them. So Narset or Shu Yun. That would give me my 'fun' Jeskai deck in a format that is more laid back and would perhaps let me have a laugh whilst doing janky stuff.

Then I'll probably build a W/R deck for the new standard.

It's useful. I could happily pick that up and have fun with it

I resemble that remark 

Yeah, Narset is good anywhere in either version. Go girl

I'm inclined to agree. There is potential in jeskai I think.

Bestow and prowess work - as far as I am aware a bestow creature cast as an enchantment is an enchantment spell when on the stack regardless of it's other types on the card (see MTG Salvation rules discussion for use of Negate against an attempted bestow) as the choice of 'what' it is goes down to the caster when it goes on the stack.

I quite like the idea of Aquas form on something like Dragon-Style Twins followed by a titan's strength. For 2 mana you now have an unblockable 8/8 with double strike for that turn - hold a counterspell in hand for any attempts to remove it and you can get up to 18 points that turn for 4-5 mana...

Yes, I know that if you run G/R or even U/G/R you can combo dragon style twins with become immense and get lethal in one attack but green isn't jekai

I think it would be reasonably useful - especially if you were intending to keep to a low mana cost threshold of lots of little dudes. There is even a jeskai mythic (I think) that produces monk tokens - how cool is that..?

Hmm... possibly. I think putting her in there would push it firmly into a 'late game' deck and you'd want it to be spell heavy - ok that isn't so much of a problem as prowess naturally likes you to be spell heavy. I wonder though if it would be truly competitive with her casting cost?

I think that having her in there would very much determine the nature of the spells you had in the deck - you'd want a lot of protection or bounce type spells in order to be able to survive and keep your creatures around long enough to bring her out and then to have the counterspells to stop non-targeting boardwipes. You'd also however want a certain amount of burn or combat tricks in order to lever her ability - so there is already a slight conflict between what you might have in your deck.

I think if you are levering jeskai for the colors then Narset plus enchantments, counterspell and combat tricks along with midrange creatures is viable. You deploy efficient threats until you find narset then try to clear house with her.

Or if you specifically want to lever prowess I think you could go for smaller creatures - topping out a dragon style twins - and lots of aggressive spells in red along with white protection spells to cause maximum damage and avoid blockers.

The two styles could potentially be meshed together but it would need a lot of playtesting.

All of it looks good fun though

To me 'cunning' equates as 'combat tricks and counterspells' and... sadly... morph

Use tokens as incidental and concentrate on white's instant speed protection spells.
Use blue for card draw, triggering prowess and counterspells - also potentially tapping opponents creatures..
Use red for aggressive creatures and combat tricks like double strike.

I'm inclined to agree. Ultimately the feature ability is prowess so fast is good as it puts more creatures onto the battlefield to benefit from prowess triggers and make combat maths a genuine nightmare for your opponents.

Normally I don't worry about card draw - being a player of Jund I'm more than happy to topdeck - but here we really want to keep at least 3 cards in our hand at all time if possible as with lots of 1-2 mana instants that represents between 1 and 3 prowess triggers during a combat phase - regardless of the spell's actual effects.

Dragon style twins would make a good top end to the deck. They are our 'finisher' if the game goes long but in an ideal world we won't actually need to cast them. I'd probably start with 3 in the deck and see just how much mana we tended to have before games ended. If our games tended to end reasonably quickly I'd drop the number down to 2 or even one as something you'd draw when the game dragged on. If we seem to be getting a lot of land I'd increase them to 4 and also consider why we are hitting so much land - is it because the game is going long frequently (if so... why? This is a aggro-midrange deck) or is our mana-base wrong?

Even in these 3 colors I'd probably be trying to err on the quicker side of aggression. It won't easily keep pace with mono-red or R/G aggro but if our instants double as answers then we can stay in the game until our threats sizes start to matter more.

I like something like Aquas form in this deck as it guarantees a hit as well as triggering prowess on the turn it is used.

Fetch lands I would consider strongly but I'd need to think about the number - Initially 6 springs to mind and mainly in the colors that would dig for our '3rd' color - blue. White will provide a lot of our creatures along with red and the majority of protection and burn will also crop up there. Blue gives us a set of counterspells and aquas form so perhaps 3-4 islands and 4 fetchlands that can dig for islands would give us a total of maybe 8 lands that could potentially represent drawing blue mana out of a 22-24 land mana base which is reasonable as exactly a third of our mana base. Flooded strand would provide redundancy - allowing us to fetch plains if we have actually drawn our islands

Aside from that mana ramp shouldn't really be needed. With 24 lands and at least a 2 land opening hand we should hit our land drops and have things to do each turn. What we really want are threats and instants which represent prowess triggers - anything else needs to really justify it's place.

Ok, I know that technically instant's aren't the only way to trigger prowess but for us they are likely to be the most efficient as we can use them on either players turn and having open mana on our side represents a threat our opponent must consider when attacking. Also Soulfire Grand-master can really lever those if played at the end of our opponents turn and help us regain the life we may have lost on the way.