Bosses
Bosses, oftentimes phrasally referred to as boss NPCs, are transcendent battle NPCs that can be challenged by qualifying players for an assortment of high-end rewards and feature-unlockings.
Since bosses constitute the strongest NPC-deployed lineups in the game—having maximal stats, 100 EVs across the board, and even exceeding the maximal levels that are attainable by players—they are considered the fulcrum of the PvM (player versus monster) aspect in Pokémon Revolution Online.
Boss NPCs are identifiable with their distinctively red-colored names on the overworld. Some bosses might not be visible to the players until their prerequisites have been satisfied.
Boss-NPC characters are predominantly modeled after either Gym Leaders, staff members, or plot characters.
Requirements
Given their enviable rewards and stature as cream-of-the-crop end-game content, they typically will impose lofty requirements in order to be challengable.
While requirements will boss-specifically vary, there are many commonalities and baselines that are shared among them; the more prevalent ones include 200-plus hours of playtime and six level-100 on-hand Pokémon.
Rewards
Some boss NPCs are compulsory in order to unlock essential features or progressional thresholds; for example, Youngster Joey must be defeated in order to advance to Hoenn, since he will occlude the transregional porter thereto until he is defeated. For the most part, however, boss NPCs are optional to battle but tremendously rewardful for those who defeat them, as they offer Pokémon, items and other commodities that might not be as handily obtainable, otherwise.
Incremental thresholds
While prizesets will boss-specifically vary, most of them follow the same paradigm of reward-distrubiting. Most offer initially randomized prizes—typically enviable Pokémon or items at commensurately varying odds—until the incremental thresholds are met; typically after three-consecutive wins against the boss, they will allow you to select the prize, sometimes augmenting the selectable prizes to extra prizes that might not be rewardable, otherwise.
The consecution of battles will reset either upon losing to the boss or after the third-consecutive win. Bosses typically will remind you what streak you are on after defeating them.
Pokémon
Many bosses will reward Pokémon that might either be unhuntable or ultra-rare, otherwise.
Boss-rewarded Pokémon may also have potential shiny counterparts, but most stipulate that the incremental thresholds must be met before the shiny chance is possible.
Miscellaneous
Many bosses are also multifunctional in the sense that they may serve as vendors or as move tutors. In these cases, they typically will require being battled at least one time before their commercial services are accessible; this entails that the requirements are satisfied, or they may not have any accessibly serviceable feature.
Supplementarily, an amount of Pokémoney ranging from 
1-10,000 will also be rewarded upon defeating the NPC.
Challengable bosses
Active
All presently challengable bosses are tabulated hereunder. Click on the boss name to access its individualized page for much more elaborate information regardingly.
Discontinued
All bosses on the tabular list below are discontinued bosses, meaning that they previously existed but were removed from the game, made inaccessible, or have been substantially reworked.
| Boss | Region | Location | Cooldown |
|---|---|---|---|
| 9oomy & Gouseru | Kanto | Love Island (House 1) | 12 days |
| Greinjack | Johto | In front of Blackthorn City's Pokémart | 12 days |
| Guardian Kaguya | Phantasm Land | Unison Mountain Summit | 2 days |
| Kagawa | Vulcan Island | Kalijodo Lake | 6 days |
| Mayor Gorge | Phantasm Land | Unison Mountain 3F | 2 days |
| Officer Wargreymon | Kanto | Pewter City Jail | 12 days |
| Old Lady Janice | Hoenn | Lilycove City (Motel 2F) | 12 days |
| Ravine | Hoenn | Mt. Pyre Summit | 12 days |
| Sgath & Keres | Kanto | Love Island (House 1) | 12 days |
| Shieon | Cryofrost | Mistpeak Valley House | 12 days |
| Summer Guardian Lime | Vulcan Island | Kalijodo Lake | Not rechallengable |
| Summer Guardian Rin | Vulcan Island | Vulcan Island Shore | Not rechallengable |
| Zetsu | Phantasm Land | Bittersweet Cave 4F | 3 days |
Cooldown time
Amount
Most bosses will be rechallengable after 12 days have elapsed; the main exceptions are quest-compulsory bosses, which either cool down after 2 hours or will not be rechallengable by virtue of the fact that simply battling them will suffice to unlock the progressional reward.
Naero is another anomaly, wherein the boss' cooldown time will be halved to six days if battled with active membership status at the juncture the battle was initiated.
Cooldown-timers
The cooldown times can be checked by speaking to the cooldown-checker in Celadon Office 2F, Goldenrod City House 1, Slateport City House 1, or Canalave City House 1; they will give you a confirmatory response as to whether or not they are ready.
If you seek a more quantitative answer on the remaining cooldown time, you can interact with the boss in question; they will quantify how much time is remaining before they are rechallengable when asked.