Cestus summoning condition allows you to put a GB monster onto the field without using up your normal summon, and this fixes a problem - exacerbated by Master Rule 4 the archetype inherently suffers from, which is, getting that crucial second GB monster onto the field to make a strong first turn play

Provided Decklist: Monsters: 26 | Earthbound Immortal Ccapac Apu ||| Earthbound Greater Linewalker | Grapha, Dragon Lord of Dark World | Diabolica, Dragon Fiend Commander ||| Earthbound Prisoner Stone Sweeper ||| Snoww, Unlight of Dark World | D/D Gryphon ||| Genta, Gateman of Dark World | Dark Spirit of Banishment | Dark Spirit of Malice ||| Earthbound Prisoner Line Walker ||| Earthbound Prisoner Ground Keeper || D/D Lamia Spells: 14 | Dark World Dealings ||| Dark Corridor | Harmonic Synchro Fusion | Dark World Accession || Dark Contract with the Gate ||| The Gates of Dark World ||| Earthbound Prison Extra Deck: | Grapha, Dragon Overlord of Dark World | Earthbound Servant Geo Grasha || Earthbound Servant Geo Kraken | Hot Red Dragon Archfiend Abyss | Scar-Red Dragon Archfiend | Red Dragon Archfiend || Earthbound Servant Geo Gryphon | Ancient Pixie Dragon || Earthbound Servant Geo Gremlin | Muddy Mudragon | T.G

While not as prevalent as Ash Blossom, many players use Ghost Mourner as an alternative to interrupt opponents' combos
negate the Summon or activation, and if you do, destroy that card. Let us begin with Thunder King Rai-Oh
Quote If a card in your Pendulum Zone(s) or a Spellcaster monster is targeted by your opponent's effect: Target 1 Wyrm monster you control that would be an appropriate target