This combo turns Treasures into damage with Bats ping on Token entry/exit and Fireweaver on Artifact entry
Use protective sleeves, binders, and card boxes to prevent damage from dust, sunlight, or moisture
It's literally an Unclaimed Territory 99.99% of the time as spending 6(!) total mana to make a 1/1 Sliver token is such an awful rate that it might as well not even be on the card -- if you regularly activate it then I'd recommend rebuilding the deck, maybe add some more card draw so you have better things to spend your mana on

WHITE | BLUE | BLACK | RED | GREEN MULTICOLORED | ARTIFACT | LAND | ALL CARDS WHITE Coppercoat Vanguard Deification Harnessed Snubhorn Metropolis Reformer Spark Rupture Tazri, Stalwart Survivor Coppercoat Vanguard Deification Harnessed Snubhorn Metropolis Reformer Spark Rupture Tazri, Stalwart Survivor Deification Metropolis Reformer Spark Rupture Tazri, Stalwart Survivor Coppercoat Vanguard Deification Harnessed Snubhorn Metropolis Reformer Tazri, Stalwart Survivor Spark Rupture BLUE Filter Out Tolarian Contempt Training Grounds Vesuvan Drifter Filter Out Tolarian Contempt Training Grounds Vesuvan Drifter Training Grounds Vesuvan Drifter Filter Out Tolarian Contempt Training Grounds Vesuvan Drifter BLACK Ayara's Oathsworn Blot Out Death-Rattle Oni Markov Baron Urborg Scavengers Ayara's Oathsworn Blot Out Death-Rattle Oni Markov Baron Urborg Scavengers Ayara's Oathsworn Urborg Scavengers Ayara's Oathsworn Blot Out Death-Rattle Oni Markov Baron Urborg Scavengers RED Arni Metalbrow Kolaghan Warmonger Plargg and Nassari Reckless Handling Arni Metalbrow Kolaghan Warmonger Plargg and Nassari Reckless Handling Arni Metalbrow Plargg and Nassari Arni Metalbrow Kolaghan Warmonger Plargg and Nassari Reckless Handling GREEN Animist's Might Leyline Immersion Nissa, Resurgent Animist Open the Way Tranquil Frillback Undercity Upheaval Animist's Might Leyline Immersion Nissa, Resurgent Animist Open the Way Tranquil Frillback Undercity Upheaval Leyline Immersion Nissa, Resurgent Animist Open the Way Tranquil Frillback Tranquil Frillback Undercity Upheaval MULTICOLORED Calix, Guided by Fate Campus Renovation Cosmic Rebirth Danitha, New Benalia's Light Feast of the Victorious Dead Gold-Forged Thopteryx Jirina, Dauntless General Jolrael, Voice of Zhalfir The Kenriths' Royal Funeral Kiora, Sovereign of the Deep Nahiri, Forged in Fury Nahiri's Resolve Narset, Enlightened Exile Nashi, Moon's Legacy Niv-Mizzet, Supreme Ob Nixilis, Captive Kingpin Pia Nalaar, Consul of Revival Rebuild the City Rocco, Street Chef Samut, Vizier of Naktamun Sarkhan, Soul Aflame Sigarda, Font of Blessings Tyvar the Bellicose Calix, Guided by Fate Campus Renovation Cosmic Rebirth Danitha, New Benalia's Light Feast of the Victorious Dead Gold-Forged Thopteryx Jirina, Dauntless General Jolrael, Voice of Zhalfir The Kenriths' Royal Funeral Kiora, Sovereign of the Deep Nahiri, Forged in Fury Nahiri's Resolve Narset, Enlightened Exile Nashi, Moon's Legacy Niv-Mizzet, Supreme Ob Nixilis, Captive Kingpin Pia Nalaar, Consul of Revival Rebuild the City Rocco, Street Chef Samut, Vizier of Naktamun Sarkhan, Soul Aflame Sigarda, Font of Blessings Tyvar the Bellicose Calix, Guided by Fate Danitha, New Benalia's Light Jirina, Dauntless General Jolrael, Voice of Zhalfir The Kenriths' Royal Funeral Kiora, Sovereign of the Deep Nahiri, Forged in Fury Nahiri's Resolve Narset, Enlightened Exile Nashi, Moon's Legacy Niv-Mizzet, Supreme Ob Nixilis, Captive Kingpin Pia Nalaar, Consul of Revival Rebuild the City Rocco, Street Chef Samut, Vizier of Naktamun Sarkhan, Soul Aflame Sigarda, Font of Blessings Tyvar the Bellicose Calix, Guided by Fate Campus Renovation Cosmic Rebirth Danitha, New Benalia's Light Feast of the Victorious Dead Gold-Forged Thopteryx Jirina, Dauntless General The Kenriths' Royal Funeral Kiora, Sovereign of the Deep Nahiri, Forged in Fury Nahiri's Resolve Narset, Enlightened Exile Nashi, Moon's Legacy Niv-Mizzet, Supreme Ob Nixilis, Captive Kingpin Pia Nalaar, Consul of Revival Rebuild the City Rocco, Street Chef Samut, Vizier of Naktamun Sarkhan, Soul Aflame Sigarda, Font of Blessings Tyvar the Bellicose Jolrael, Voice of Zhalfir ARTIFACT Karn, Legacy Reforged Karn, Legacy Reforged Karn, Legacy Reforged LAND Drannith Ruins Drannith Ruins Drannith Ruins Drannith Ruins WHITE | BLUE | BLACK | RED | GREEN MULTICOLORED | ARTIFACT | LAND | ALL CARDS

Holons Castform was also essential in Delta Species decks like Metanite (Metagross /Dragonite ) and Raieggs (Raichu /Exeggutor ), as it gave unparalleled draw power in the early stages of the game
only 2% of the copies ever sent to get graded