Hollow Island is one of the more unique hunting experiences Rubi-Ka has to offer. This is an encampment of Eremite broods, which becomes progressively more powerful and more dangerous as the assault continues. There are a total of ten distinct Broods that an invading force must face down before the leaders of the Eremites will emerge.
To begin the Hollow Island encounter, a team must seek out the Stinking Scorpiods, which will occasionally drop an item called Scorpiod Droppings when killed. A good place to encounter these Scorpiods is just to the west of Hollow Island. When the Droppings have been acquired, the focus shifts toward Hollow Island and the Sapling.
The Sapling is initially a VERY small Sylvabane-like creature, sitting at approximately the location shown in the map below. If the Sapling is not there, it will likely sprout again sometime in the next four hours, so patience may be required. Once the Sapling has sprouted, fertilizing it with the Scorpiod Droppings will turn it into a Fast-growing Sapling, and awaken the Eremite Broods. It is very important that, at this point, the majority of the team or teams are standing at the position marked Recommended Fight Location, and only one or two people remain near the Sapling to pull the Broods.
At this point it is extremely important to note the following: once the raid has begun, the Fast-growing sapling will hibernate after a certain period of time, dependent on brood level. Typically, the hibernation will occur with the appearance of the Brood Champion. Failure to defeat the Brood Champion before it retreats to its underground lair will result in termination of the raid, as the Sapling will not come out of hibernation unless the awakened Champion is defeated. Further, killing of the sapling at any point before the conclusion of the raid or the appearance of the Champion will also terminate the raid.
Shortly after the Sapling reaches level 25, First Brood Eremites and First Brood Eremite Brutes will begin to spawn. The people left near the Sapling are responsible for pulling one to three Eremites at a time back to the teams. Depending on the level of the teams and number of people, it is important that the pulls be fairly controlled and disciplined in the early going, so the teams are in a groove, as the immunities of the Brood Eremites to Roots, Snares, Calms, and Charms increase as the Brood level increases (to the point that by the 6th Brood, there will be no Roots, no Calms, and no Charms (100% immunities)) and because the number of Eremites appearing in each brood increases significantly.
Eventually, the Brood Champion will spawn. There will be a total of 10 Champions (links 5 through 14 above) and their broods to deal with, before the true leaders of the Eremites will appear. It is advised that teams avoid the Brood Champion until the majority of Eremites and Brutes have been dispensed with. When the area near the Champion is cleared, pull the Champion the same as the regular Eremites are pulled, noting that they will begin their fights with area effect nanos, and will begin running a very destructive NanoChain when attacked. These nano chains become extremely dangerous with the higher level Champions. Indeed, the NanoChains grow to the point that the Suzerain has 5 quick instant damage attacks that hit for a cumulative 30,000 HP and the Brood Mother has a Nano Siphon DoT that absorbs 30,000 NP on all players nearby, followed by four Health Siphon DoTs that absorb 30,000 HP, 24,900 HP, 21,900 HP, and 18,900 HP respectively, followed by a wide area Stun. It is imperative that any team or raid party expecting to survive the higher level encounters bring along a Meta-physicist. None of the Eremites or Champions at Hollow Island have any immunity to Nano Shutdown, which means it will land with relative ease and render the NanoChains a moot point.
Finally, with everything else to deal with, teams should take care to avoid losing members, as those raiders that attempt to return will have to deal with the Psionic Eremites, creatures which my research indicates have the strongest individual attacks of any creature on Rubi-Ka and the ability to warp you to them at their whim. If attempting to enter Hollow Island during a raid without the ability to fly, you will be dead again, either instantly, or in two hits, or maybe, if you're lucky, three, and if at any point during the raid, either returning from death or wandering about, a settler enters their attack range, it's back to reclaim for them.
If the teams manage to take down all the Eremites, there is still the matter of bringing down the fully mature Sapling, otherwise known as the Hollow Island Weed. This version of the Sapling is a true monster, with a dangerous NanoChain of its own, three major attacks, including one against Poison AC, and its own set of minions to go with it. While the Brood Mother may seem like the final encounter, a complete raid will confront the cause of all the problems at Hollow Island.