Nightcreep

Until end of turn, all creatures become black and all lands become Swamps.

Gilt-Leaf Archdruid

Whenever you cast a Druid spell, you may draw a card.
Tap seven untapped Druids you control: Gain control of all lands target player controls.

All lands are 2/2 creatures that are still lands.

{2}{G}, {T}, Discard two cards: All lands target player controls become 3/3 creatures until end of turn. They're still lands.

All lands become 2/2 creatures until end of turn. They're still lands.