Differentiating Monsters of Varying Strengths

I've had a go at the design over here. Using the mockup as a base, I made a few changes and filled in some data to see what it'd look like. Mainly, skills are separated into "active" and "passive", where active contains skills such as Smash, Counter, Windmill ect. where "passive" contains skills such as Invulnerability, Chain-casting, Standers ect. It could also accommodate any weird tags you mentioned, of which they'd need to be defined beforehand however. As for the multiple map locations, it could be listed as |*Gairech Hill (North) ... |*Gairech Hill (Dragon Ruins) ... and if the stats are shared for the 2 places |*Gairech Hill (North, Dragon Ruins). The template is concise, but sort of messy.

Stepping back, there's also the possibility of keeping the old template and listing monsters by dungeon instead of by type. So instead of a "Bear" page, monsters for a particular area could be listed under that area. But that opens up quite a few more problems, such as duplication and general untidiness. It could be left as is, with only the mobs with variations using the new template, while any standalone mobs keep the old one to avoid wasted space, but the it'd look very inconsistent. Or perhaps location could be replaced with tabs, and stats are displayed according to which location is selected.

Idk. It's a tough problem no doubt. Gonna need to play around with a few more mockups.

I really don't like tabs. Your idea of having them per dungeon/area seems good honestly. The monster data goes into a central template so all of the relevant data can just be there and we can import it thru the relevant monster style based on the page it's in.

We could get rid of family pages (or turn them into links instead or something) and do one per monster I guess, then have locations as a gallery instead of being in the template itself?

I did some research and found that Ragnarok Online has a monster database which sparked some inspiration. Perhaps we could just use a single interface to access monster data instead of hundreds of pages? However, I can't really see the down side to too many pages unless storage is an issue. Further research shows that other games use either family pages, or single pages and list them based on area.

Couldn't find a game that has such a variety of monsters as Mabi, and the games that come close use single pages for each mob. This leads me to believe that consolidating groups of monsters on a single page probably isn't a good idea anymore.

Perhaps a good solution is turning family pages into categories, listing monsters as links on the dungeon/area page and each monster has a unique page. Additionally, on the area page, hovering over the links could provide a small amount of info on the monster such as a picture, HP, CP, Gold and EXP. Or we could swap the hovering for a collapsible table.

Edit: Also just realized if each monster had a separate page, the layout wouldn't have to be compact. We could favour readability over space.