Festering Thicket

Cycling for two rather than one is the tax written into this design: the extra generic mana is what a fixing land pays to also carry a flood valve, becoming a fresh card on the turns you already have lands enough and staying a black-or-green source on the turns you do not. The load-bearing detail is the typing. Because it is a Swamp Forest and not merely a nonbasic that taps for the same colors, it answers to anything that searches out a Swamp or a Forest, feeds domain as both basic types at once, and reads as either to the parts of a deck built around one or the other. Entering tapped is the honest offset for all that flexibility: it costs a turn of tempo, so the card wants an early drop when you can spare the beat, or it wants to leave your hand entirely via the discard option once the game has already flooded you. That two-mode identity, land when you are short and cantrip when you are long, is the whole reason to run it; every clause exists so one slot can do a land's job or a card's job depending on which the game hands you.