An opportunity to include fantasy staple villains and themes into Javelin, from Vampires to middle-eastern or far-east aesthetics. They would serve as alternate Endgame #269 content for the Epic tier, only happening in the actual World map.
There are numerous ways to implement this but perhaps the best starting point for discussion would be as Disasters #146 (which should probably be renamed to Crisis at this point). The benefits of this approach would be:
No need to neuter the Nemesis earlier, allowing him to show up at full strength for thematic impact or juggle content such as Incursions and their Encounter Level ranges to make their presence known from start to end.
Let the Nemesis be more Epic tier content, akin to classic secret-bosses in other games.
No need for a predictable, fixed set of Nemesis or power-gaming for all of 20 levels with the goal to face a known enemy (while still allowing for a healthier amount of that, depending on how early they show up procedurally). Multiple Nemesis can also spawn in a single game, if rare, given Disaster spawn rates.
All of this built into a framework already well-adjusted into the game's design and vice-versa (if not actually implemented yet).
For maximum effect, the Nemesis should probably spawn Raids (Temple-sized Dungeons) where they inhabit the lowest floor, as a special type of Fight. This is a bit hard on suspension of disbelief but given that each World Tile represents a huge area, it's not unfeasible for a Nemesis to lie dormant until late in the game. To increase variety with each playthrough, the surrounding Terrain's enemies should probably also be considered in the pool, creating interesting less-likely themes such as a Desert Vampire or powerful Mummies that dwell in mayan-like Forest ruins rather than the egyptian stereotype. Those wouldn't affect the aesthetic necessarily but definitely the gameplay inside Raids in profound manner.
If each Branch #254 had a Nemesis, it would tie several new development processes to the Branch-oriented methodology: nemesis themselves, disasters/crisis, artifacts, endgame content (as compared to mid-game Haunts)... It would require an extra piece of art for the Raids but considering Haunts are the same, it's not much of a stretch for how much content Branches add to the game. The Haunt Fight Mechanic would also serve as double-duty to make the Nemesis Fight memorable and unique, further justifying the work these complex custom routines demand.
Given that all Temples are already Branch-based, rather than Disasters these could be just procedurally-generated Raids, picking a random pool of them to be Epic-tier content, as Temples are now. If going with the Crisis approach though, these Locations should probably also Spawn incursions at a higher rate, so they feel like a proper Crisis. Maybe even a hybrid-approach is possible, with Raids being inactive until a Disaster activates them, placing a Nemesis on the lowest floor and allowing them to spawn Incursions at a high rate.
The material reward for a Nemesis Fight should probably be an Artifact #224 but that could be hard to implement and balance as the creature would ideally have to be able to use it against the player as well. Maybe when a Nemesis is dying, the player is allowed a choice to spare them and use it as a Summon instead, which would be a more convenient type of Artifact while also extremely powerful. For this to not completely break the game, the Nemesis would need to fit a CR15-20 range, which is not too powerful, while the Fight itself can be higher EL with the additions of other Raid Encounters or Branch Monsters.
An opportunity to include fantasy staple villains and themes into Javelin, from Vampires to middle-eastern or far-east aesthetics. They would serve as alternate Endgame #269 content for the Epic tier, only happening in the actual World map.
There are numerous ways to implement this but perhaps the best starting point for discussion would be as Disasters #146 (which should probably be renamed to Crisis at this point). The benefits of this approach would be:
For maximum effect, the Nemesis should probably spawn Raids (Temple-sized Dungeons) where they inhabit the lowest floor, as a special type of Fight. This is a bit hard on suspension of disbelief but given that each World Tile represents a huge area, it's not unfeasible for a Nemesis to lie dormant until late in the game. To increase variety with each playthrough, the surrounding Terrain's enemies should probably also be considered in the pool, creating interesting less-likely themes such as a Desert Vampire or powerful Mummies that dwell in mayan-like Forest ruins rather than the egyptian stereotype. Those wouldn't affect the aesthetic necessarily but definitely the gameplay inside Raids in profound manner.
If each Branch #254 had a Nemesis, it would tie several new development processes to the Branch-oriented methodology: nemesis themselves, disasters/crisis, artifacts, endgame content (as compared to mid-game Haunts)... It would require an extra piece of art for the Raids but considering Haunts are the same, it's not much of a stretch for how much content Branches add to the game. The Haunt Fight Mechanic would also serve as double-duty to make the Nemesis Fight memorable and unique, further justifying the work these complex custom routines demand.
Given that all Temples are already Branch-based, rather than Disasters these could be just procedurally-generated Raids, picking a random pool of them to be Epic-tier content, as Temples are now. If going with the Crisis approach though, these Locations should probably also Spawn incursions at a higher rate, so they feel like a proper Crisis. Maybe even a hybrid-approach is possible, with Raids being inactive until a Disaster activates them, placing a Nemesis on the lowest floor and allowing them to spawn Incursions at a high rate.
The material reward for a Nemesis Fight should probably be an Artifact #224 but that could be hard to implement and balance as the creature would ideally have to be able to use it against the player as well. Maybe when a Nemesis is dying, the player is allowed a choice to spare them and use it as a Summon instead, which would be a more convenient type of Artifact while also extremely powerful. For this to not completely break the game, the Nemesis would need to fit a CR15-20 range, which is not too powerful, while the Fight itself can be higher EL with the additions of other Raid Encounters or Branch Monsters.