Is that meant to be "end of combat"?

Architect of Naktamun
Creature — Bird Cleric
Flying
Whenever you cycle or discard a card, put a brick counter on target artifact.
Artifacts you control have "Remove a brick counter from this artifact: Untap this artifact."
"Kefnet blessed me with this wisdom so that I may bring this world closer to paradise."
1/2

Oh, duh. Yeah.

Sunscoured Shade

Creature -- Shade (R)
Sunscoured Shade can't block.
You may cast Sunscoured Shade from your graveyard as long as you've cycled or discarded a card this turn.
Cycling
3/1

Lonely Twin
Creature — Jackal Warrior
Haste, trample
Lonely Twin enters the battlefield with a +1/+1 counter.
Survivor (At end of your combat, put a +1/+1 counter on this creature if it attacked this combat.)
At the beginning of your end step, remove a +1/+1 counter from Lonely Twin.
2/0

Hunter of the Dunes

Creature -- Wurm (U)
This spell has flash as long as you control a Desert.
When Hunter of the Dunes enters the battlefield, you may have it fight target creature you don't control.
The sands of the Hekma move according to the whims of the wind above them and the beasts below them.
4/4

Enforcer of the God-Pharaoh
Creature — Angel
Flying
When Enforcer of the God-Pharaoh enters the battlefield, if it entered the battlefield from the graveyard or if it was cast from the graveyard, destroy all creatures with lesser power.
Eternalize
5/3

Levees of the Luxa
Artifact
: Mill a card. If a land card is milled this way, return it to your hand. Put a brick counter on Levies of the Luxa.
, Remove three brick counters from Levees of the Luxa: Untap all lands you control. Activate this ability only as a sorcery.
"As the banks overflow, so must your heart overflow with love for the God-Pharaoh." — Hazoret, god of zeal

Shimmering Expanse
Land -- Desert (C)
: Add .
, , Sacrifice Shimmering Expanse: Search your library for a Desert card, put it onto the battlefield tapped, then shuffle your library.
It's not a mirage, but it's also not what it appears.

Ixalan

Messenger Raptor
Creature — Dinosaur
Enrage — Whenever Messenger Raptor is dealt damage, draw a card.
Information flows up and down the terrace roads like blood to the heart of the Sun Empire.
2/1

Under the new paradigm of white getting draws to punish opponents...does this work?

Kitesail Corsairs
Creature - Human Pirate
Flying
When ~ enters the battlefield, return it or a Treasure you control to its owner's hand.
"We charge a modest fee for our services, but I assure you we're worth every gold piece."
[2/2]

@neru: I like it in white.

Bloodbanner Conquistador

Creature -- Vampire Soldier (R)
Whenever Bloodbanner Conquistador attacks, pay any amount of life. Bloodbanner Conquistador gets +X/+0 until end of turn, where X is the amount of life paid.
The hatred of a vampire is always undying.
3/3

Black Scale, Bane Of The Skyways
Legendary Creature - Dragon Pirate
Flying
Whenever you sacrifice a treasure, put a +1/+1 counter on ~ and it deals 2 damage to any target.
At the beginning of your end step sacrifice each Treasure you control.
5/3
"Never ken'd the point in hoarding. Coin unspent's naught but wasted coin."

Is "Skyways" a stretch, or can we just assume that's a thing Ixalan could have in Return To Ixalan?

I'm not sure what you're suggesting with "Skyways", but I have made like Sun Empire airplane invasion of Torrezon references in this thread before, since they've found fuel.

Migratory Greatbill
Creature — Dinosaur
Enrage — Whenever Migratory Greatbill is dealt damage, it explores.
The River Heralds do not master animals like the Sun Empire not because they cannot but because they do not believe in doing so.
0/4

Mosasaur Guardian
Creature - Dinosaur
If a source would deal more than 1 damage to another creature you control, it deals all but 1 of that damage to ~ instead.
"Remember; every hatchling has two deadly progenitors." - Hualti
[3/5]

Goblet of Redemption
Artifact
Whenever a creature enters the battlefield, put a charge counter on Altar of Redemption.
Whenever a creature dies, remove a charge counter from Altar of Redemption.
At the beginning of your end step, you may remove five charge counters from Altar of Redemption. If you do, transform Altar of Redemption.

Tabernacle of the Fast
Legendary Land
: Add .
All creatures have "At the beginning of your upkeep, destroy this creature unless you pay ."
Only the Redeemed are allowed in the holiest sites on the holiest days but the Dusk Legion's human servants do not mind.

Conqueror's Coffers
Land (U)
: Add .
, Tap X untapped Treasures you control: Add X mana of any one color.
"A city of gold? I don't know if my ships' holds can carry that much, but I'd be happy to try." —Captain Dray

Shandalar

Bani Bakur of Ardestan
Legendary Creature — Human Soldier
When Bani Bakur enters the battlefield, search your library for a legendary card, reveal it, shuffle, then put it on top of your library.
Whenever a legendary creature or planeswalker you control dies, destroy target legendary creature or planeswalker an opponent controls.
3/3

Elastic-Mind Observer
Creature — Sliver
Slivers you control have "When this Sliver enters the battlefield, learn."
It is not only physical adaptations that spread rapidly among the hive.
2/2

Ravenous Swarmer
Creature — Sliver
Slivers you control have "When this Sliver dies, destroy target creature or enchantment an opponent controls with mana value equal to this Sliver's mana value. You lose that much life."
A hunger greater than one belly.
1/1

Rage Sliver
Creature - Sliver
Slivers you control get +3/+0 and have "At the beginning of your end step sacrifice this creature if it attacked this turn."
A hunger greater than one belly.
2/2

Expand the Hive

Sorcery (U)
Search your library for a basic land card or a Sliver card and reveal it. If it's a basic land card, put it onto the battlefield. Otherwise, put it into your hand. Then shuffle.