Dropping the roleplaying for a moment, this mod adds a basic terraforming tool.
It lets you mark two points (left/right click) and then use the /fillblocks [block] [optional:meta] command to fill the area with the desired block type.
To replace only specific blocks: /replaceblocks [newBlock] [oldBlock] [optional:meta]
To scatter the desired block type across the target zone: /scatterblocks [block] [percentage] [optional:meta] (percentage is a "per block" chance to be replaced with the desired block.)
Shortcuts: /fblocks, /rblocks and /sblocks.
Sunshine and flowers not included.
This tool is only usable in creative mode and while holding it. (Meaning you can have multiple tools for different areas.)
The [block] parameter is using the new block identifiers, ie "minecraft:dirt". Or "minecraft:air".