Pigly's Lava Rising

Start a lava rising game with /start. Customise the start height and rise rate using the plugin config. You can also change it to void instead of lava. Every "lava tick", all blocks at the next Y level (within the world border) will be replaced with lava (or void depending on configuration). Lava ticks end when the next level would be 320. The plugin sets the world border to 100x100 blocks.