0.8.10 Tumble working increasing cost of all spells

Tried it without perks and with just the Blademaster and Wolpertinger, it happens even without any cascading gems in the party.
Platform is Windows 10
Party Data in details

Summary

========== CHARACTER ==========
DS the Rune Knight
Achievement Points: 847 / 4079 (21%)
Time Played: 124:18:43
Game Version: 0.8.10

Total Perk Points: 1550

========== CREATURES ==========
Level 1465 Apis Majesty
Fused with Ebony Ent
Apis / Nature

Health: 14527
Attack: 5876
Intelligence: 7484
Defense: 8804
Speed: 9386

Innate Trait: Necessitarianism
At the start of battle, this creature gains 100% Attack, Intelligence, Defense, and Speed. This creature deals 70% less damage.
Fused Trait: Nature’s Blessing
Your creatures always have Mending.

Artifact: Kind Shoes
59% Speed
36% Defense / Speed
59% Defense
36% Defense / Speed
3 Spell Gem Slots
(Empty Trick Slot)
Kindness
(Empty Spell Slot)

Trait Slot: Kindness: Your creatures have additional Attack, Intelligence, Defense, and Speed equal to 15% of this creature’s respective stats.

Spell Gems:
Wormhole
Dispel
Mass Dispel
Frost Rampart
Dark Whispers
Reverse Polarity


Level 1465 Blademaster
Fused with Imp Necromancer
Brownie / Nature

Health: 14967
Attack: 7924
Intelligence: 5289
Defense: 7044
Speed: 12319

Innate Trait: Overkill
After this creature Attacks, and the damage exceeds 35% of the target’s Maximum Health, enemies take 70% of this damage as well.
Fused Trait: Darkness Fate
Your creatures have 7% more Speed for each permanent Nature Spell Gem each of your creatures have equipped. Maximum of 3 Spell Gems per creature. This trait does not stack.

Artifact: Gateway
59% Speed
59% Speed
59% Speed
59% Speed
84% Spell Potency
30% Damage Reduction
Spook
(Empty Spell Slot)

Trait Slot: Spook: At the start of battle, this creature gains Invisible. This creature deals 200% more damage while it is Invisible. This creature’s Invisible buff is no longer removed at the start of its turn.

Spell Gems:
Dust Cloak
Constriction
Stone Ward

Relic: Petra & Aes, War Drums of Meraxis (Rank 10)

Level 1465 Vicious Wolpertinger
Fused with Eternaldew Gemling
Wolpertinger / Sorcery

Health: 8814
Attack: 7924
Intelligence: 11732
Defense: 7924
Speed: 8804

Innate Trait: Colorblind
After this creature Attacks, it Casts a Scourge spell that matches the target’s class.
Fused Trait: Tumble
Your creatures’ Spell Gems with the Cascading property now consume 3 Charges when cast, and are 50% more potent. This trait does not stack.

Artifact: Lotus Staff
59% Intelligence
59% Intelligence
59% Intelligence
59% Intelligence
84% Spell Potency
30% Damage Reduction
Black Lotus
(Empty Spell Slot)

Trait Slot: Black Lotus: Your creatures take 40% less damage while they have Mending. This trait does not stack.

Spell Gems:
Black Ice
Steel Storm
Drain Power

Relic: Thousand Needles, Honed Bow of Apocranox (Rank 50)

Level 1465 Crystal Smith
Fused with Nix Informer
Smith / Death

Health: 18185
Attack: 7924
Intelligence: 8364
Defense: 8364
Speed: 5583

Innate Trait: Fool’s Axiom
Your creatures have additional Defense equal to 50% of the total Defense bonus on this creature’s artifact.
Fused Trait: Supersonic
At the start of battle, enemies are afflicted with Silenced for 1 turn.

Artifact: Phaser
59% Defense
59% Defense
59% Defense
59% Defense
30% Damage Reduction
(Empty Trick Slot)
Endurance Aura
(Empty Spell Slot)

Trait Slot: Endurance Aura: Your creatures take 80% less damage from all sources other than attacks and spells. This trait does not stack.

Spell Gems:
Decay
Vitality Explosion
Misery

Relic: Ferro, Great Axe of Gonfurian (Rank 28)

Level 1465 Apis Guardian
Fused with Amaranthine
Apis / Life

Health: 14087
Attack: 7924
Intelligence: 5723
Defense: 13492
Speed: 5289

Innate Trait: Grit
At the start of battle, this creature’s Attack is added to its Health and Defense, then its Attack is set to its minimum value.
Fused Trait: Incandescence
At the start of battle, this creature gains Maximum Health equal to 150% of its Defense.

Artifact: Helmet
49% Health
49% Health
49% Health
49% Health
(Empty Trick Slot)
(Empty Trick Slot)
Royal Authority

Trait Slot: Royal Authority: This creature always has Protected and Repelling, and Defends at the end of its turn.

Spell Gems:
Requiem
Holy Protection
Godly Gin

Relic: Triumvir, Arcane Sceptre of Zonte (Rank 30)

Level 1465 Carver Shadowstalker
Fused with Martyaxwar
Carver / Chaos

Health: 18772
Attack: 9685
Intelligence: 8364
Defense: 6163
Speed: 5583

Innate Trait: Subversion
This creature’s attacks deal 75% more damage and afflict the target with Disarmed.
Fused Trait: Mouth For War
After this creature Casts a single-target spell on an enemy, it also Attacks that enemy 2 times.

Artifact: Type-B
59% Attack
59% Attack
59% Attack
59% Attack
30% Critical Chance
84% Attack Damage
Outrage
(Empty Spell Slot)

Trait Slot: Outrage: This creature is always Berserk, and deals 75% more damage while this buff is active.

Spell Gems:
Frost Rampart
Chaos Channeling
Conflagration


Thanks, fixed in the next patch!