You've got 11 (10 without the fetch) fixing lands, Ghostfire Blade and 10+ playable morphs in U/G/R alone. I think I'm on the UGxx Morph plan. In fact, in this case it may be more like the URxx Morph deck.
Your powerful cards are Jeskai centered, and your manafixing lets you play anything. So I'd go for the 5-colour mess here. The big decision is which colours are going to be your base and have your two-drops. That looks like blue and red here.
Coloured mana
U 8+1 source for 6/4 cards/morphs
R 4+6 source for 5/5 cards/morphs
W 3+1 source for 2/2 cards/morphs
B 4+ source for 1/2 cards/morphs
G 4+0 source for 0/4 cards/morphs
Curve (Counting Ashcloud Phoenix as a 4 and Horde Ambusher as a 2 since I think that's where we want to play them)
1 s
2 cccss
3 ccccccccccs
4 cc
5 cs
6 s
I'm going to disagree on the BW there. Your only three black cards also require white mana, which means that Sandsteppe Citadel doesn't even fully count as B & W here. Moreover, they're just not powerful enough cards to justify 6 comes into play tap lands that only fix for 4 cards in your deck. Especially give that you've got cards of similar power levels in the two main colours (Treasure Cruise, Riverwheel Aerialists, Burn Away) that don't even make your list.
I can see how having all these fixing lands could make you greedy, but in this case I don't think it's worth it.
Yeah, I can see that. On second cut you can pretty easily cut the Ankle Shanker and both Ponyback Brigade for Scaldkin, Riverwheel Aerialists and Treasure Cruise. That will give you another 2 basics instead of [card]Dismal Backwater[card] as untapped lands to help curve out with.
2 Alabaster Kirin
1 Erase
2 Mardu Hordechief
1 Siegecraft
1 Suspension Field
1 Take Up Arms
Blue
2 Crippling Chill
1 Disdainful Stroke
2 Embodiment of Spring
1 Force Away
1 Glacial Stalker
2 Jeskai Windscout
1 Mistfire Weaver
1 Monastery Flock
2 Riverwheel Aerialists
1 Scaldkin
1 Treasure Cruise
1 Waterwhirl
1 Wetland Sambar
Black
1 Bitter Revelation
3 Debilitating Injury
2 Kheru Dreadmaw
1 Molting Snakeskin
1 Sultai Scavenger
1 Throttle
1 Ainok Tracker
1 Arc Lightning
1 Ashcloud Phoenix
1 Bloodfire Expert
1 Bloodfire Mentor
1 Bring Low
2 Burn Away
1 Horde Ambusher
1 Leaping Master
1 Mardu Heart-Piercer
1 Tormenting Voice
1 Trumpet Blast
1 Valley Dasher
Green
1 Awaken the Bear
1 Hooting Mandrills
1 Longshot Squad
2 Naturalize
1 Sagu Archer
1 Scout the Borders
1 Windstorm
2 Woolly Loxodon
Gold
1 Ankle Shanker
1 Icefeather Aven
1 Master the Way
2 Ponyback Brigade
1 Snowhorn Rider
1 Temur Ascendancy
1 Ghostfire Blade
1 Heart-Piercer Bow
3 Jeskai Banner
1 Lens of Clarity
1 Ugin's Nexus
Land
2 Dismal Backwater
1 Mystic Monastery
1 Opulent Palace
1 Rugged Highlands
1 Sandsteppe Citadel
2 Swiftwater Cliffs
1 Thornwood Falls
1 Tranquil Cove
1 Windswept Heath
I'll put up a specific list later.
1 Leaping Master
1 Horde Ambusher
1 Glacial Stalker
1 Icefeather Aven
2 Ponyback Brigade
1 Snowhorn Rider
2 Woolly Loxodon
1 Mistfire Weaver
2 Jeskai Windscout
1 Ashcloud Phoenix
1 Mardu Heart-Piercer
1 Ankle Shanker
1 Force Away
1 Suspension Field
1 Arc Lightning
1 Master the Way
1 Waterwhirl
2 Dismal Backwater
1 Mystic Monastery
1 Opulent Palace
1 Rugged Highlands
1 Sandsteppe Citadel
2 Swiftwater Cliffs
1 Thornwood Falls
1 Tranquil Cove
6 Mountain
1 Island
1 Plains
Coloured mana
U 8+1 source for 6/4 cards/morphs
R 4+6 source for 5/5 cards/morphs
W 3+1 source for 2/2 cards/morphs
B 4+ source for 1/2 cards/morphs
G 4+0 source for 0/4 cards/morphs
Curve (Counting Ashcloud Phoenix as a 4 and Horde Ambusher as a 2 since I think that's where we want to play them)
1 s
2 cccss
3 ccccccccccs
4 cc
5 cs
6 s
Yeah, I can see that. On second cut you can pretty easily cut the Ankle Shanker and both Ponyback Brigade for Scaldkin, Riverwheel Aerialists and Treasure Cruise. That will give you another 2 basics instead of [card]Dismal Backwater[card] as untapped lands to help curve out with.