Riftbound Deathknell
None of the 37 cards with Deathknell print a reminder explaining it, so there is no official wording to quote here. Rather than guess at the rule, the cards themselves are below.
Which domains get it
Which sets print it
Every card with Deathknell
Most expensive first. Prices are Cardmarket EUR.
Lonely Poro
Unleashed · 2 energy
EUR 149.95
Rift Herald
Unleashed · 8 energy
EUR 8.00
Rift Herald
Unleashed · 8 energy
EUR 6.63
The Zero Drive
Spiritforged · 3 energy
EUR 6.00
Sprite Fountain
Unleashed · 2 energy
EUR 3.92
Scuttle Crab
Unleashed · 2 energy
EUR 3.77
LeBlanc - Fragmented
Unleashed · 3 energy
EUR 3.75
Ferrous Forerunner
Spiritforged · 6 energy
EUR 3.67
Karthus - Eternal
Origins · 3 energy
EUR 1.89
Tasty Faefolk
Origins · 7 energy
EUR 1.45
Clocktower Guardian
Radiance · 8 energy
EUR 0.65
Ekko - Recurrent
Origins · 5 energy
EUR 0.50
Hunting Dog (Radiance Nexus Night Promo)
Radiance · 3 energy
EUR 0.50
Machine Evangel
Origins · 5 energy
EUR 0.39
Unsung Hero (Spiritforged Nexus Night Promo)
Spiritforged · 2 energy
EUR 0.38
Sacred Shears
Spiritforged · 2 energy
EUR 0.30
LeBlanc - Fragmented
Unleashed · 3 energy
EUR 0.25
Kog'Maw - Caustic
Origins · 3 energy
EUR 0.23
Glasc Mixologist
Spiritforged · 5 energy
EUR 0.17
Loyal Poro
Unleashed · 3 energy
EUR 0.14
Noxian Emissary
Vendetta · 2 energy
EUR 0.12
Lonely Poro
Spiritforged · 2 energy
EUR 0.11
Loyal Poro (Unleashed Nexus Night Promo)
Unleashed · 3 energy
EUR 0.10
Mournful Spirit
Radiance · 4 energy
EUR 0.10
Soaring Scout
Origins · 2 energy
EUR 0.10
Baccai Witherclaw
Vendetta · 4 energy
EUR 0.08
Carrion Dredger
Unleashed · 2 energy
EUR 0.08
Black Rose Dignitary
Unleashed · 3 energy
EUR 0.07
Honest Broker
Spiritforged · 2 energy
EUR 0.07
Unsung Hero
Spiritforged · 2 energy
EUR 0.07
Hunting Dog
Radiance · 3 energy
EUR 0.05
Watchful Sentry
Origins · 2 energy
EUR 0.05
Ruined Rex
Unleashed · 6 energy
EUR 0.04
Undercover Agent
Origins · 5 energy
EUR 0.04
Dramatic Visionary
Unleashed · 4 energy
EUR 0.03
Detonation Amplifier
Radiance · 4 energy
EUR 0.02
Gravity Field
Radiance · 5 energy
EUR 0.02