Whenever a unit with Meld is positioned on top of a Node tile on the overland map, the orders menu displays a button labeled "Meld". When this button is pressed, the unit attempts to gain control of the Node for its owner. The unit is immediately destroyed, but if the Melding process is successful, this Node will boost the Power rating of the unit's controller.
There are only 2 units in the game that possess this ability: the Magic Spirit and the Guardian Spirit. No other unit can ever have the ability to Meld under any circumstances. The Guardian Spirit's Meld ability, while indistinguishable in-game, is actually stronger: once it Melded with a Node, any further attempts at Melding have only a 25% chance of success - thus making it harder for enemy wizards to retake that Node.
Nodes are places in the real world where a hole has been punctured into one of the Magical Realms. A large amount of raw magical Power seeps constantly through the hole, but is initially unfocused. A unit with Melding capabilities can sacrifice itself in order to shape this seepage into a controllable stream. As a result, the unit's controller can channel this Power at will, using it like any other source of Power in the game - resulting in increased magical prowess.
Due to the large amounts of energy involved, the Melding unit is destroyed completely during the process.
In order to use its Meld ability, a unit must move to an overland tile containing a Node. Naturally, since Nodes are initially Encounter zones (and often filled with powerful creatures), it is necessary to first clear the defenders. The Melding unit can participate in such a battle, but is often better sent in afterwards when all is safe.
Once the unit is on top of the Node, the unit's orders menu will display a button labeled "Meld". This button will only ever appear for units possessing the Meld ability, and is greyed-out while the unit is not on top of a Node.
Once this button is pressed, the Melding process takes place immediately. In the majority of circumstances, it will be successful (the possibility of Melding failure is discussed further below).
The result is that the affected Node now falls under the control of the unit's owner. The Node will now provide a certain amount of Power directly to that owner, increasing his/her Power rating. The exact amount of Power provided by the Node depends on several factors, including its location (Arcanus or Myrror), the current Magic Intensity setting, and even random factors.
Visually, the Node's tile as well as several tiles around it will now continuously sparkle. The color of the sparkles is the same as the color of the wizard controlling this Node, indicating its ownership.
Once a Node is under a wizard's control, it will remain that way permanently - unless another Melding unit from a different empire arrives at the Node and manages to Meld with it. In that case, ownership is immediately transferred to the unit's owner. A Node may change hands an unlimited number of times during a single game. This is one good reason why a wizard who gains control of a Node will likely try to fortify it with a strong army - so that enemies would have to defeat that army before they can make any attempt at Melding with this Node.
A unit activating its Meld ability is always destroyed on the spot. It sacrifices itself in order to channel the abundant energy to its master.
Melding Failure Edit
There are two important cases where Melding either cannot be used or can fail, changing the rules describing above.
The first case is when a Node is under the effect of the Warp Node spell. While affected, the Node reduces its owner's Power instead of increasing it - and it cannot be Melded with. A Melding unit sitting on top of such a Node will not be able to activate its Melding ability at all. Thus, the Warped Node's owner is "stuck" with this Power sink, and must either live with it or use Disenchant Area to remove the spell.
The second case occurs when a Guardian Spirit successfully Melds with a Node. Once this happens, any subsequent attempt by other empires to Meld with that Node have only a 25% chance of success. In other words, if any unit attempts to Meld with the node, it has a 75% chance of failure. Note that the attempt destroys the unit (as described earlier) whether it was successful or not.
Units with Default Meld Edit
There are exactly two units in the game that possess the Meld ability. Both are Fantastic Creatures:
The Magic Spirit is an Arcane creature, and is available for summoning to all wizards as soon as the game begins. Thus, all wizards have the potential ability to Meld with and control Nodes, straight from game-start.
The Guardian Spirit is only available to Life-wielding wizards, and not necessarily to all of them. Aside from increased combat performance, the Guardian Spirit has a stronger version of the Meld ability: once it successfully Melds with a node, any further attempt by any other unit to Meld with the same Node has only a 25% chance of success. Read more on this above.
Acquiring Meld Edit
The Magic Spirit and Guardian Spirit are the only two units in the game that possess the Melding ability. It is not possible for any other unit to acquire this ability in any way, neither through spells nor through Magical Items. This is what makes Spirits so valuable despite their general lack of combat prowess.