Bog Down [Planeshift]

Bog Down [Planeshift]Set: Planeshift Type: Sorcery Rarity: Common Cost: {2}{B} KickerSacrifice two lands. (You may sacrifice two lands in addition to any other costs as you cast this spell.) Target player discards two cards. If this spell was kicked, that player discards three cards instead.

leading to the chaos of the Three Kingdoms

and even houses

Either we take it down or it'll take down the Fair

Set: Commander Anthology Type: Land Rarity: Uncommon {T}: Add {C}

Put the chosen cards into your graveyard and the rest into your hand

ripping itself a new entrance

its controller adds an additional {G}

Set: Dominaria Prerelease Promos Type: Legendary Artifact Rarity: Mythic Cost: {0} {T}: Add one mana of any color among legendary creatures and planeswalkers you control

Set: Unlimited Edition Type: Creature — Gargoyle Rarity: Rare Cost: {2}{R} Flying

Set: Modern Masters 2017 Type: Land Rarity: Mythic As Cavern of Souls enters the battlefield

but how do we get down

if another creature is on the battlefield