That doesn't hose the previous card much--protection won't stop it from getting bounced by an untargeted effect. (Also, it should have protection from Shapeshifters; I don't think "protection from ability" works that way). If only you'd given it a creature type.
Hosing both:
Horrible Moment B
Tribal Instant--Horror
Until end of turn, permanents you control are Horror Tribals in addition to their types.
Target creature gets -2/-2 until end of turn.
Should regenerate the creature, otherwise if a creature has lethal damage the game goes into an infinite loop.
That Hideous Strength 1BG
Instant
Until end of turn, whenever an opponent gains life, choose a permanent that player controls, destroy it, and draw a card.
Mindtide Moon 2U
Enchantment 2: Exchange control of target Island and target blue creature.
Mindtide Moon has "Cycling 0" as long as you've drawn two or more cards this turn.
Trick the Changeling G
Tribal Instant--Kithkin
If you control a Kithkin, draw a card.
This turn, if an activated or triggered ability of a Shapeshifter would resolve, instead counter it and that Shapeshifter becomes a 0/1 green Insect creature with no abilities until end of turn. "Bet you can't turn into a fly."
Level Seeker 2U
Creature--Elemental
4/4
When Level Seeker enters the battlefield, if a player controls fewer blue permanents than you do, that player gains control of Level Seeker.
Form of Ice and Fire 1UR
Enchantment--Aura
Enchant creature
You control enchanted creature.
Enchanted creature's power is equal to the number of red permanents you control, and its toughness is equal to the number of blue permanents you control.
Shared Intensity 2R
Sorcery
Each player adds RRRRR to his or her mana pool.
Until end of turn, whenever mana drains from a player's mana pool as a phase ends, that player loses that much life.
Temporal Anomalies5UUU
Enchantment
Choose a phase, there is an additional one of those phases after every normal phase.
Both of these look like they're meant to hose Flux Matrix, so I'll hose them both.
Dark Defender 3(W/G)
Creature--Spirit
0/4
Defender 1B,T: Attacking creatures get -2/-2 until end of turn. 1U, sacrifice Dark Defender: Counter target artifact or enchantment spell.
Machinegod Supplicant WW
Creature--Human Cleric (MR)
2/2
Artifact creatures with converted mana cost 5 or greater have "When this creature enters the battlefield, double your life total."
You probably didn't mean for that to give the controller infinite mana, right?
Treacherous Servant B
Creature--Human Rogue
1/1
If an Eldrazi Spawn token would enter the battlefield, put a +1/+1 counter on Treacherous Servant instead. T: Destroy target Eldrazi creature with power less than Treacherous Servant's power.
WUBRG
Creature--Avatar
5/5
Return Invincible Champion to your hand: You gain 5 life.
Make a card called Long For This World.
Hosing both:
Horrible Moment
B
Tribal Instant--Horror
Until end of turn, permanents you control are Horror Tribals in addition to their types.
Target creature gets -2/-2 until end of turn.
Make a card called Long For This World.
That Hideous Strength
1BG
Instant
Until end of turn, whenever an opponent gains life, choose a permanent that player controls, destroy it, and draw a card.
Make a card called Long For This World.
2U
Enchantment
2: Exchange control of target Island and target blue creature.
Mindtide Moon has "Cycling 0" as long as you've drawn two or more cards this turn.
Make a card called Long For This World.
1UU
Tribal Instant--Wizard
Cascade
Counter target spell if you control a Wizard.
Make a card called Long For This World.
G
Tribal Instant--Kithkin
If you control a Kithkin, draw a card.
This turn, if an activated or triggered ability of a Shapeshifter would resolve, instead counter it and that Shapeshifter becomes a 0/1 green Insect creature with no abilities until end of turn.
"Bet you can't turn into a fly."
Make a card called Long For This World.
2U
Creature--Elemental
4/4
When Level Seeker enters the battlefield, if a player controls fewer blue permanents than you do, that player gains control of Level Seeker.
Make a card called Long For This World.
1UR
Enchantment--Aura
Enchant creature
You control enchanted creature.
Enchanted creature's power is equal to the number of red permanents you control, and its toughness is equal to the number of blue permanents you control.
Make a card called Long For This World.
2R
Sorcery
Each player adds RRRRR to his or her mana pool.
Until end of turn, whenever mana drains from a player's mana pool as a phase ends, that player loses that much life.
Make a card called Long For This World.
1R
Instant
Add to your mana pool. You can't spend this mana to cast spells.
Gravestorm
Make a card called Long For This World.
G
Enchantment
Blue and/or black spells that target a green permanent or spell you control cost an additional to cast.
Make a card called Long For This World.
G
Enchantment
If a spell or ability would reduce the toughness of a creature you control to 0 or less, it reduces it to 1 instead.
Make a card called Long For This World.
Both of these look like they're meant to hose Flux Matrix, so I'll hose them both.
Dark Defender
3(W/G)
Creature--Spirit
0/4
Defender
1B,T: Attacking creatures get -2/-2 until end of turn.
1U, sacrifice Dark Defender: Counter target artifact or enchantment spell.
Make a card called Long For This World.
WW
Creature--Human Cleric (MR)
2/2
Artifact creatures with converted mana cost 5 or greater have "When this creature enters the battlefield, double your life total."
Make a card called Long For This World.
Treacherous Servant
B
Creature--Human Rogue
1/1
If an Eldrazi Spawn token would enter the battlefield, put a +1/+1 counter on Treacherous Servant instead.
T: Destroy target Eldrazi creature with power less than Treacherous Servant's power.
Make a card called Long For This World.