These kinds of designs are interesting thought experiments, though too niche/obscure to show up in an actual magic product aside of maybe playtest cards in Mystery boosters.
That aside, it does work as printed and I don't think with would be that much of a balance problem since its sorcery speed. In the wild mongrel example, for instance, you can't surprise you opponent to blow them out with multiple repeated activations so if you pump a bunch before combat they can just chump, and any extra copies of Hot Air that you draw are effectively dead draws
1
Counter target spell if all lands of its controller are tapped.
1
Backstrike: if defending creature doesn't have it, attacking creature deals 1 damage to it. It could be 2 damage by adding color hate, a white creature being blocked by a creature that is both black and red. I wouldt restrict the color hate to bicolor because there are just too many small creatures across all colors, meaning that 2 damage against monocolored creatures seems too much.
Stone Skin: when this creature blocks, it gets +0/+1 until end of turn. Maybe +0/+2. It's not damage prevention or protection and it's restricted to combat cases. I thought about being target of a spell or ability, but it would be meaningless against all "destroy" effects.
Last Stand: it's the opposite of Exalted. Whenever a creature you control blocks alone, it gets +1/+1 until end of turn.
1
Land
T: Add one mana of any color. Spend this mana only to cast spells with a converted mana cost of 1 or activate abilities that cost one mana.
1
Instant
Return target nonland permanent to its owner’s hand. Its controller discards 2 cards and Bolas’ Cruelty deals 3 damage to any target.
[b]Underworld Cry[/b] 1BU
Sorcery
Exile all cards from target player’s graveyard. For each card exiled this way, that player puts the top card of their library in their graveyard.
[b]Rakdos' Nuke[/b] 4BR
Sorcery
Destroy all creatures and planeswalkers.
Hellbent — If you have no cards in your hand, each player discards their hand.
[b]Peacewalker[/b] 1W
Creature - Human Advisor
1W, T: Tap target creature. If it’s black or red you gain 2 life.
1/2
[b]Ghost Shock[/b] BRU
Instant
Counter target spell, triggered or activated ability. Ghost Shock deals 2 damage to that spell’s controller and they discard a card.
[b]Frightening Horror[/b] 3BB
Creature - Horror
Flying, menace
When Frightening Horror dies, each opponent loses 5 life.
5/5
[b]Goblet of Life[/b] 4
Artifact
Whenever you cast a spell, you gain 1 life for each card with the same name as that spell in your graveyard.
[b]Rakdos' Spectacle[b] 2BR
Enchantment
Whenever a creature you control deals combat damage to an opponent or planeswalker they control, Rakdos’ Spectacle deals 2 damage to each creature they control unless they discard a card.
[b]Leila, Dark Witch[/b] 1BBRR
Legendary Creature - Human Wizard
Whenever a demon, imp, devil or horror you control deals combat damage to an opponent, that player discards a card and Leila, Dark Witch deals 2 damage to any target.
5/5
1
1
Rathi Dragon. Liked the art and the flavour text.
Rolling Thunder. Liked the art (the older Tempest art)
Exhume. Cool art.
Mana Breach. Liked the flavour text from Exodus.
Order of the white shield, order of the sacred torch and Knight of Dawn. Because the art is beautiful.
1
Legendary Land
T: Add C to your mana pool.
T: Add WUBRG to your mana pool. Activate this only if you control a basic land of each basic type.
In a last minute change I added legendary. Atlhough the condition to tap it for 5 mana is hard, maybe it's not that hard.
1
Sorcery
Double the number of counters on target permanent.
Inspired by Doubling Season
False Guide W
Creature - Human
When False Guide dies, exile target creature.
1/1
False Prophet little
Honor the Dead 1WW
Enchantment
Whenever a creature you control dies or is exiled, you gain 1 life.
In the first version it triggered for creatures leaving the battlefield, but I thought it could create life gain loops.
Growing 3G
Sorcery
Double the number of counters on target permanent.
//
Rotting 2B
Sorcery
Remove all counters from target permanent.
This my first time trying a split card. In the first version it was multicolored with two modes, then I felt it was better to go split card.
Knight of Exile 2WB
Creature - Knight
First strike
When Knight of Exile enters the battlefield, exile another target creature.
2/2
It started at 3 mana without first strike, then I raised the mana cost and added first strike.
Spiritual Bond 2WB
Enchantment
Creatures you control have lifelink.
WB: Prevent all damage that would be dealt to target creature. You lose that much life.
I could template it with damage redirection as in Spirit en-kor, but with the activation cost being WB I felt that preventing damage and losing life fitted better. I tried using hybrid B/W, but damage redirection doesn't feels black alone.
Prismatic Seal WG
Enchantment
Cards in your graveyard can’t be target of spells or abilities.
You may spend mana as though it were mana of any color to pay the activation costs of abilities of cards in your graveyard.
Ground Seal + Celestial Dawn.
Punish nonbasic lands 1UR
Instant
Tap all nonbasic lands, they don’t untap during its controller next untap step.
Punish nonbasic lands deals x damage to each player, where x is the number of nonbasic lands he or she controls.
In the first iteration it was a sorcery, but I think that it's more useful as an instant.
Lifebond WW
Enchantment
Whenever a creature you control is dealt damage, you gain 1 life.
I tried some variations with "you control the source of damage" vs "you don't control the source of damage" and damage prevention. What I realized is that preventing 1 damage adds to board complexity because it forces players to subtract 1 of every amount of damage. Plus, having two triggers, one for you and another for the other players adds to the card's complexity without making it better to play with.
Minimum Damage 1W
Enchantment
If a source would deal exactly 1 damage to anything, it deals 0 damage instead.
Could be non symmetrical.
Put fire out with gasoline 2R
Enchantment
If a source would deal exactly 1 damage to anything, it deals 2 damage instead.
The red version of the above.
Surprise! UU
Instant
If an effect or ability an opponent controls would cause you to discard one or more cards, draw two cards instead.
1
Instant
Copy Spell can’t be countered by spells or abilities.
Copy target instant or sorcery spell. You may choose new targets for the copy. The copy can’t be countered by spells or abilities.
Quick Attack RG
Instant
Target creature gets +3/+3 and gains haste until end of turn.
Chalice of the Heart x
Artifact
Chalice of the Heart enters the battlefield with x heart counters.
Whenever a player casts a spell with converted mana cost equal to the number of heart counters on Chalice of the Heart, you gain that much life.
Underworld Rider 3WB
Creature - Archon
Flying
When Underworld Rider enters the battlefield, you gain 1 life for each card in your hand.
When Underworld Rider dies, each opponent loses 1 life for each card in your hand.
3/3
1
Legendary Artifact
T: Destroy all permanents target player controls. Activate this only if you control a white ranger, a blue ranger, a black ranger, a red ranger and a green ranger.
And there would be a race of creatures with the type "Ranger" to make it work.
Seriously though, it's more a joke card despite working within the rules. I had an idea for legendary artifacts that can only be activated if a certain legendary creature is on the battlefield. Or artifacts that belong to one race of creatures, can only equip a certain subype for example.