Obsianus Golem + Scourge of the Throne

Obsidian Scourge
Artifact Creature - Golem (R)
During additional combat phases, switch Obsidian Scourge's power and toughness.
Whenever Obsidian Scourge attacks for the first time each turn, untap all attacking creatures named Obsidian Scourge. After this phase, there is an additional combat phase for creatures named Obsidian Scourge.
4/6

Scourge of the Throne + Foriysian Totem

Hellkite Idol
Kindred Artifact - Dragon
: Add one many of any color. Spend this mana only if it is , to cast Dragon spells you control, or to activate abilities of Dragon permanents you control.
: ~ becomes a 4/4 red Dragon creature with Flying and Haste until end of turn, then untap each other creature you control. After this phase, there is an additional combat phase. Activate only as a sorcery and only once per turn.

Foriysian Totem + Raise Dead

Risen Gravemarker
Artifact
: Add .
Imprint — , : Exile target creature card from your graveyard.
, Pay the mana cost of a creature card exiled with this artifact: This artifact becomes a copy of that creature card. (Its other abilities are replaced.)

raise dead + form of the dragon

Form of the Dragon + Tenacious Underdog

Rise of the Riveteers
Enchantment — Saga
I - Target creature you control fights target creature you don't control.
II - Return target creature from your graveyard to the battlefield. It gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.
III - Transform Rise of the Riveteers.

Ziatora's Bargain
Enchantment
If you would lose the game, exile Ziatora's Bargain instead. If you do, your life total becomes 5, Ziatora's Bargain deals 5 damage to any target, and create five Treasure tokens. At the beginning of your next end step, you lose 5 life.
The other dragons scorned her, because she liked fighting petty knights more than hoarding gold. Now the other dragons are all gone and she has the biggest hoard of all.

Tenacious Underdog + Mimic Vat

Deja Vu Machine
Artifact (R)
, : You may put a creature card with mana value X or less from your hand onto the battlefield. It gains haste. Exile it at the beginning of the next end step.
: You may put a creature card exiled with ~ onto the battlefield. It gains haste. Exile it at the beginning of the next end step.

Mimic Vat + Bloodrite Invoker

Eternity Invoker
Creature — Vampire Warlock
: Exile target creature card from a graveyard. Create a token that's a copy of that creature card except it's a colorless Eldrazi with base power and toughness 8/8.
1/3

Bloodrite Invoker + Warp World

Warpwhirl Invoker
Creature - Goblin Shaman (C)
Menace
: Exile target artifact, creature or land. Its controller reveals the top card of their library. If it's a permanent card, they put it onto the battlefield. Otherwise, they put it into their hand.
3/2

Random ironically works to my favor:

Warp World + Essence Flux

Existence Flux
Sorcery
Each player puts their graveyard on the bottom of their library, then shuffles all permanents they own into their library. Each player then reveals cards from the top of their library equal to the cards from the battlefield and puts all artifact, creature, and land cards revealed this way onto the battlefield, then does the same for enchantment cards, then puts all cards revealed this way that weren’t put onto the battlefield into the graveyard.
Put a +1/+1 counter on each Spirit you control.
"In one terrible moment, the veil of the afterlife fell and the living and the dead no longer recalled from whence they came..."

Essence Flux + Pale Recluse

Presence in the Pale Mist
Creature — Spirit
Flying
When this creature enters from anywhere except exile, exile it. When you do, create a tapped Forest Island land token.
, Sacrifice a land: Put this creature card from exile onto the battlefield.
4/4

pale recluse + the master, gallifrey's end

The Master, Gallifrey's End + Death Denied

Deny the People Their Grief
Sorcery — Arcane
Return a creature card from any graveyard to the battlefield unless an opponent pays 3 life. Repeat this X times, where X is the number of times a card was spliced onto this spell.
Splice onto Arcane
"Perhaps the greatest mercy the kami offer is that in our deaths, we will join the realm of the victors." —Sensei Hisoka, letter to Lord Konda

Death Denied + Howling Galefang

Sidisi's Plot
Sorcery (R)
This spell costs less to cast for each card you own in exile.
Return X target creature cards from your graveyard to your hand.
The tyranny of the dragonlords had to end to make room for a new kind of tyranny.

Howling Galefang + Leyline of Hope

Junkyard Pack
Creature - Dog
~ gets +2/+2 as long as your graveyard is empty.
"I bet that one is too busy wondering what that strange hunk of scrap is to watch over the rest of the yard."
[2/2]

Weirdly, another leyline for random.

leyline of hope + leyline of void

Leyline of Zen
Enchantment
If Leyline of Zen is in your opening hand, you may begin the game with it on the battlefield.

If a card would be put into a graveyard from anywhere, exile it instead. You gain 1 life for each card exiled this way.

As long as you have at least 5 life more than your starting life total, creatures you control get +2/+2.

leyline of the void + icatian moneychanger

Icathian Moneychanger + Test of Endurance

Abzan Imperialist
Creature — Human Advisor
Remove fifty +1/+1 counters from Abzan Imperialist and sacrifice it: You win the game.
Outlast—Pay 1 life
1/1

Test of Endurance + Subtle Strike

Half-Life
Sorcery (R)
Choose any number of target players. Each of those players' life total becomes half their starting life total, rounded down.
All Magic decays over time. But time can be tampered with.

subtle strike + fact or fiction

Fact or Fiction + Mishra's Factory

The Room Where it Happens
Land (U)
This land enters tapped. As it enters, an opponent chooses three colors.
: Add one mana of any of the chosen colors.