The first Triforce dungeon, "Forest Temple", is in need of a boss. Now, a familiar well-trodden dungeon concept calls for a familiar, well-trodden boss concept. It will look like this:
Why yes, it is a World Tree that is ancient as time and tall as the sky. How did you guess it so quickly?
It is called Deku, and those that bear its curse (which, for reasons outlined previously, cannot include Link) are called Deku Scrubs. And it is indeed the one responsible for that destroyed town in the forest. Like all plants, it is thoroughly amoral and unemotional. Only when a brave wizard inflicted those charring burns to its roots did Deku relent from spreading its forest any further.
It doesn't have a face, either. Why not? Because plants don't have faces! Rather, lacking a face brings to mind a superintelligent alien monolith, but made of wood.
It does indeed hold the Triforce of Courage. But, it no longer trusts humanity with the Golden Power, and vows never to release it, and certainly not to one working for the family of Hyrule. Thus, a duel of sorts must be waged.
Link's first sword, his "magic stick", is a branch that was wrongly taken from Deku. His "magic stick" is also quite indestructible. This leads one to assume that a direct offensive to the whole tree will not work well. Furthermore, Deku itself claims that as long as it has the spring water of the Fairy of Spring, it cannot be weakened.
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This boss battle and its cutscenes haven't been programmed yet. That being said, I propose the following battle plan:
Phase 1 - Puzzle
* The weak spots are the burnt roots protruding into the water. Hitting one of the roots with fire or bombs will simply cause the other root to regenerate its hearts. Link must therefore hit both at roughly the same time. This requires burning one root while a bomb explodes on another.
* Deku continually summons those little tendril monsters, and drops lit Bomb Flowers in front of Link when he is away from the roots.
Phase 2 - Combat
* Link must burn or bomb one of the burnt roots until its hearts drop to 4.
* Deku uses telekinesis to pull branches, boulders and blocks from the left and right of the screen, and hurl them at Link one-by-one.
Phase 3 - Transition
* Deku magically summons pouring rain, which causes it to regenerate hearts, and prevents Link from creating fire or lighting bombs.
* Deku continues using telekinesis attacks.
* Link realises that he must therefore attack somewhere else.
* Vines spontaneously sprout around the central roots. Link must climb onto those vines, then shoot the hookshot upward at a low-hanging branch.
Phase 4 - Climbing
* Link must climb up Deku's trunk in Sideview mode for several screens, using the hookshot to grab thick branches, shimmy along convenient platforms formed from outward shoots, and climb up some branch-dwelling vines. The pouring rain and telekinetic attacks continue unabated, but are joined with blowing wind - pushing Link to the left. Since Link cannot jump, he will need to be launched out of Deku Flowers (which will be used elsewhere in the quest) as well. Falling off the bottom of a screen is considered to be "drowning".
* In the two topmost screens, Link must climb through the rain clouds. (The resultant obscured vision will be built, I think, from three simultaneous identical transparent layers of gray.)
Phase 5 - Sideview Combat
* And since we need a climax, let's put some kind of big monster inside the cloud as well. Some kind of all-scripted Gohma beast who fires small spears of lightning and whose eye must be dragged down to sword-level with the hookshot.
Victory Sequence
* After that, Link breaks through to startling blue sky - and to the leaf canopy of the tree. Just as he is about to set fire to Deku's leaves, the boss surrenders. Beneath the giant leaves, in the glory of the sun, the Triforce of Courage is granted.
Umm, yeah. Since this is NeoFirst, it can't hurt to pull out the stops for a Triforce boss, could it?