Devoted Combo wants to chain Devoted Druid, Green Sun's Zenith and Agatha's Soul Cauldron into a huge Craterhoof Behemoth turn. Damping Sphere makes each spell a player casts cost {1} more for each other spell they have already cast that turn, which slows down any turn where they try to chain several spells together. Their mana mostly comes from creatures like Devoted Druid and from Leyline of Abundance's bonus mana, none of which the Sphere's land clause touches, so the spell tax is the reason it comes in. Static Prison is a weaker removal piece here since it only holds a permanent for as long as we keep paying energy at the start of our first main phase, so it comes out for more proactive disruption. Keep our clock fast since this matchup is often a race if disruption doesn't fully lock them out.