Koma, World-Eater

This spell can't be countered.
Trample, ward {4}
Whenever Koma deals combat damage to a player, create four 3/3 blue Serpent creature tokens named Koma's Coil.

This spell can't be countered.
Fry deals 5 damage to target creature or planeswalker that's white or blue.

Surrak Dragonclaw

Flash
This spell can't be countered.
Creature spells you control can't be countered.
Other creatures you control have trample.

Toski, Bearer of Secrets

This spell can't be countered.
Indestructible
Toski attacks each combat if able.
Whenever a creature you control deals combat damage to a player, draw a card.

Abrupt Decay

This spell can't be countered.
Destroy target nonland permanent with mana value 3 or less.

Caught Red-Handed

This spell can't be countered. (This includes by the ward ability.)
Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. Suspect it. (It has menace and can't block.)

Lithomantic Barrage

This spell can't be countered.
Lithomantic Barrage deals 1 damage to target creature or planeswalker. It deals 5 damage instead if that target is white and/or blue.

Combust

This spell can't be countered.
Combust deals 5 damage to target white or blue creature. The damage can't be prevented.

Koma, Cosmos Serpent

This spell can't be countered.
At the beginning of each upkeep, create a 3/3 blue Serpent creature token named Koma's Coil.
Sacrifice another Serpent: Choose one —
• Tap target permanent. Its activated abilities can't be activated this turn.
• Koma gains indestructible until end of turn.

Inevitable Defeat

This spell can't be countered.
Exile target nonland permanent. Its controller loses 3 life and you gain 3 life.

Volcanic Fallout

This spell can't be countered.
Volcanic Fallout deals 2 damage to each creature and each player.

Supreme Verdict

This spell can't be countered.
Destroy all creatures.

Frenzied Baloth

This spell can't be countered.
Trample, haste
Creature spells you control can't be countered.
Combat damage can't be prevented.

Shifting Ceratops

This spell can't be countered.
Protection from blue (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything blue.)
{G}: This creature gains your choice of reach, trample, or haste until end of turn.

Wilson, Refined Grizzly

This spell can't be countered.
Vigilance, reach, trample
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Choose a Background (You can have a Background as a second commander.)

Balustrade Wurm

This spell can't be countered.
Trample, haste
Delirium — {2}{G}{G}: Return this card from your graveyard to the battlefield with a finality counter on it. Activate only if there are four or more card types among cards in your graveyard and only as a sorcery.

Long Goodbye

This spell can't be countered. (This includes by the ward ability.)
Destroy target creature or planeswalker with mana value 3 or less.

Thrun, Breaker of Silence

This spell can't be countered.
Trample
Thrun can't be the target of nongreen spells your opponents control or abilities from nongreen sources your opponents control.
During your turn, Thrun has indestructible.

Raze to the Ground

This spell can't be countered.
Destroy target artifact. If its mana value was 1 or less, draw a card.

Slice from the Shadows

This spell can't be countered. (This includes by the ward ability.)
Target creature gets -X/-X until end of turn.

Glen Elendra's Answer

This spell can't be countered.
Counter all spells your opponents control and all abilities your opponents control. Create a 1/1 blue and black Faerie creature token with flying for each spell and ability countered this way.

Banefire

Banefire deals X damage to any target.
If X is 5 or more, this spell can't be countered and the damage can't be prevented.

Last March of the Ents

This spell can't be countered.
Draw cards equal to the greatest toughness among creatures you control, then put any number of creature cards from your hand onto the battlefield.

Mistcutter Hydra

This spell can't be countered.
Haste, protection from blue
This creature enters with X +1/+1 counters on it.

Altered Ego

This spell can't be countered.
You may have this creature enter as a copy of any creature on the battlefield, except it enters with X additional +1/+1 counters on it.

Thrun, the Last Troll

This spell can't be countered.
Hexproof (This creature can't be the target of spells or abilities your opponents control.)
{1}{G}: Regenerate Thrun.

Magic Missile

This spell can't be countered.
Magic Missile deals 3 damage divided as you choose among one, two, or three targets.

Counterflux

This spell can't be countered.
Counter target spell you don't control.
Overload {1}{U}{U}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Void Rend

This spell can't be countered.
Destroy target nonland permanent.

Lightning Mare

This spell can't be countered.
This creature can't be blocked by blue creatures.
{1}{R}: This creature gets +1/+0 until end of turn.

Prowling Serpopard

This spell can't be countered.
Creature spells you control can't be countered.

Wreak Havoc

This spell can't be countered.
Destroy target artifact or land.

Spellbreaker Behemoth

This spell can't be countered.
Creature spells you control with power 5 or greater can't be countered.

Tyrranax Rex

This spell can't be countered.
Trample, ward {4}, haste
Toxic 4 (Players dealt combat damage by this creature also get four poison counters.)

Slaughter Games

This spell can't be countered.
Choose a nonland card name. Search target opponent's graveyard, hand, and library for any number of cards with that name and exile them. Then that player shuffles.

Terra Stomper

This spell can't be countered.
Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)