Manor Gate

Most Gates lock two named colors at printing, a fixed pairing you accept when you sleeve the card up. This one refuses to name its second color until it hits the battlefield. Green is the constant; the partner is a decision you make on entry, which turns a rigid dual into a green-anchored source that can point at whatever single splash the deck happens to need. The trade is the familiar tapped-fixer tax: a turn of untapped mana surrendered for the flexibility to choose late. The "choose a color other than green" clause does the real design work. Strip it out and a player could name green, ending up with a tapped mono-green source no better than a Forest for fixing purposes. Barring the green pick forces the land into its intended shape: hold the green base, reach for the off-color. It also carries the Gate subtype, which stops being a footnote in any deck that counts Gates or triggers on the type, so the flexibility comes stapled to membership in a family that occasionally pays out.