Level drain idea works for me. It doesn't need to be permanent, since level drain is high level magic, he could just be trying to get to another Druid powerful enough to remove it's hold on him. Or it could be a curse of the Absolute or the witch that binds him, just as easily, to use something more nebulous than a standard spell that requires a specific remedy at Moonrise or wherever. As an outsider to the brainworm thing, Halsin would still have a clear interest in keeping tabs on us, just because he's still trying to do what an archdruid is supposed to do. Even in a plot induced state of relative weakness, he could have a different angle and running commentary from the druidic perspective. Clearly mind flayers running about, spreading some kind of illidith plague like invasion of the body snatchers, is going to be bad news for the natural realm writ large so he's got that motivation going. Here's another simple plot device rationale to explain why an Archdruid might leave the Grove...
from the old "
Complete Druid's Handbook" AD&D supplement, the section on Archdruids:
Might be a moot point, or maybe not lol
ps. oh, found a link with the relevant text transcribed. The level scaling is different in more recent editions, but the core concepts are still pretty much there. I'd also like some treatment of Druidic secret languages or some kind of ogham too. I think it would be good to introduce this material via a companion like Halsin rather than via some random lorebook, or just expecting players to already know all this stuff. The Shadowdruid material would likewise be better handled by a companion too, with Kagha the obvious candidate there, but that's another thread. Anyhow, this stuff... starting on pg 45.
"
High-level DruidsOnly a limited number of druids in a given circle can reach the inner circle—nine of druid rank, three archdruids, and a single great druid. A character cannot replace one of these druids without having sufficient experience. In addition, a vacancy must open up, or the rising druid must defeat one of the current higher-level characters the druidic challenge to assume a new rank. Some tension exists between druids of the inner circle, since they remain constantly aware that a subordinate may be preparing a challenge. Unlike clerics, who normally settle down by this point, high-level druids continue adventuring as part of their duties and to stay in shape to fend off challengers.
DruidsUpon reaching 12th level, a character receives the official title druid, of which a circle never has more than nine. (Lower-level characters, though called “druids” by most, are technically “initiates.”) A druid’s role in the circle resembles that of a 7th- to 11th-level initiate, with some exceptions. At 12th level, a druid has gained access to the commune with nature spell and should use it along with other druidic resources to aggressively root out emergent threats to the wilderness within a domain. Druids attend the High Council of the Moot (described later this chapter) and always act based on the needs of the circle as a whole. The circle’s great druid at times asks 12th-level druids for advice and sends them on missions for the good of the circle. But the life of a druid involves more than just adventuring—serving as a mentor takes up much of a druid’s time, too. Selecting young people to train as druidic candidates constitutes a major responsibility of those who reach druid rank. Each year druids (and other inner circle members) pick the single most worthy of their advanced students to initiate into the Order as 1st-level druids. (For more on initiations, see Chapter 4: Role-playing Druids.)
ArchdruidsA 13th-level druid is called an archdruid. Each circle can have only three archdruids and, as with the druid rank, advancement requires either filling a vacancy or winning a challenge against a seated archdruid. An archdruid’s role resembles that of a druid, with two differences. Archdruids concern themselves more with maintaining the balance of Nature, making sure no one alignment or ethos comes to utterly dominate the domain. Also, archdruids spend time training to step into the role of the great druid. To accomplish both these goals, they devote much time to travel, ensuring their familiarity with the geography—human, natural, and magical—throughout the domain.
The Moot The three archdruids share the druid’s responsibility for initiating newcomers to the Order. In addition, they each have the right to summon a moot: a gathering of the entire circle, traditionally held at the solstices and equinoxes. By ancient custom, moots are called four times a year at these set dates, once by each archdruid and once (usually in spring) by the great druid. A moot on a nontraditional date means the summoner sees something so deeply amiss in the domain that the entire circle must discuss it as soon as possible.
These gatherings enable the circle to celebrate the changing of the seasons, to gossip and socialize, to exchange information on the state of the domain, and to fight druidic challenges before an audience. Druids at a moot perform ceremonies to celebrate Nature, honor their dead, marry a couple within the Order, and initiate new 1st-level druids. Along with these ceremonial duties, small groups at moots disappear together into the wilds to talk quietly while searching for herbs or mistletoe. The climax of any such gathering is the High Council of the Moot; the circle’s nine druids, three archdruids, and great druid meet in a secret location to discuss the state of the domain and make plans to rally the circle against a particular problem, if necessary. Sometimes an ambassador from a neighboring circle (usually a character of at least druid rank) or an emissary of the Grand Druid attends a council. These personages bring news and greetings—and sometimes requests for help. After the High Council, the great druid (or an archdruid) addresses the entire moot, answers questions, and takes advice. To call a moot, an archdruid (or the great druid) sends messengers out across the domain to spread the word to druids of all branches. All members of the circle above 7th level must attend or explain the absence. Members of 3rd to 6th level may come, but usually do so only if their journeys bring them to the vicinity or if they have business with others there. Those of 1st or 2nd level may attend a moot only with the permission of a member of the inner circle.
The moot is scheduled to begin two weeks after the summoner dispatches the announcements, giving all druids in the circle enough time to settle their business and arrive. Such a gathering generally takes place at a sacred grove under the stewardship of the summoner. Though most moots last about four days, the meeting cannot end until the summoning archdruid or the great druid dissolves it. Bards, elves, rangers, swanmays, and other sylvan folk often are invited to a moot, but its location remains a secret to others. In troubled times, elves, rangers, friendly beasts, or forest creatures may patrol the moot and take trespassers prisoner. If the domain’s circle is on good terms with the land’s rangers, a spring or autumnal moot may take place in conjunction with a rangers’ forgathering. (See Chapter 10: Forgatherings in The Complete Ranger’s Handbook.) However, like rangers, druids prefer to keep their gatherings to themselves, and such cooperation usually results from personal friendships between the great druid and notable rangers—or signals a desperate alliance against a greater foe."