A card with Phyrexian mana symbols in its mana cost is each color that appears in that mana cost, regardless of how that cost may have been paid
Discarding a card and sacrificing a creature are both part of Ruthless Disposals cost
In: 2 Disdainful Stroke 1 Essence Scatter 1 Strategic Betrayal 2 Soul-Guide Lantern 1 Loch Mare 1 Bitter Triumph 1 Tragic Trajectory 1 The Unagi of Kyoshi Island Out: 3 Requiting Hex 1 Spell Snare 1 Phantom Interference 1 Preacher of the Schism 2 Deep-Cavern Bat 2 Tishanas Tidebinder Its debatable whether you want to keep Preacher of the Schism on the play, but its going to be an expensive card that feeds right into their plan
If you do this on your opponents end step, you might just untap, drop Demon of Dark Schemes, and then steal the Emrakul, the Promised End out of their graveyard
Felidar Retreat is a four mana White Enchantment that gives you two options whenever a Land enters under your control
These tools allow you to experiment with new strategies, optimize your decks for Ranked matches, and have fun testing creative builds in Casual Play