Enemy stats multiplier for second quest

Okay, looks like my project is going into yet another direction in its specifications.

I've ended up settling on an extended story after the initial campaign - one part second quest, another part new game plus and the other two parts "game in a game". What I'd like to discuss here is strategies for statistic multipliers in ordinary battle situations that raise stats on nearly every foe you encounter (except boss actors, of course) to account for the fact that you've completed the main story and now have extended chapters to deal with should you choose to do so. As always, if this evolves from concept building to something definitive (either in requisite or result) I will defer to wherever the mods see fit to direct further discussion.

This is definitely the kinda of thing I would do. However, just boosting enemies' stats isn't enough I think. Only seeing higher numbers doesn't feel much of an improvement. I would at least give enemies' new skills, if not abilities.

http://yanfly.moe/2016/01/29/yep-64-enemy-levels/
http://yanfly.moe/2015/10/18/yep-15-base-troop-events/

have base troop so every encounter will check switches (or variable)
and enemy levels plugin commands to alter the enemy's levels based on the switches/variable
have boss fights turn on a "Boss Battle" switch for conditional branch so those fights dont use the same level system
(remember to also have the switch turn off as part of the event)

and like @MushroomCake28 mentioned
enemy levels has a note tag to have enemies use new skills as they become stronger
<Skill x Require Level: y>

great system to use for new game+ (or darkworld alteration) as you wouldnt want to be a bore going through old places
and having end game content that is harder then the final boss is basically a staple in most games

@MushroomCake28 Agreed, few things are more annoying that enemies that relies on high stats to be difficult, that was one of the main reason why i dropped a fangame when i reached the post-game, fighting the old Dungeon Bosses that you managed to beat with good strategy only to be flattened because their stats went sky high is frustrating, especially when the most reliable strategy to beat those Enhanced Bosses was overleveling or cheesing them.

@Tiamat-86 Please note that 'Game Mechanics Design' is for looking at aspects of game play at a more conceptual level. Implementation (for example, the plugins etc. that you mentioned) does not belong here, especially as this is meant to be an engine neutral section.

Please everyone, note that the OP asked for a discussion of strategies for statistic multipliers.

Granted, this only applies to the second quest in my case. I do also have a "deja vu" mechanic (that is, a central hub that leads to rematch versions of the higher priority boss actors) but that is a separate matter for my purposes.

One other thing: does there happen to be anything in the same respect for multiples upon XP accumulation towards the next rank/level/etc? EDIT: Turns out this is already built in and so as a request it's now totally redundant.

EDIT 2: Also, I should note that strategies can also extend to suggestions and that is where the plugins came in for all I know. I consider this a part of the planning process as much as the discussion itself so that when I do the implementation I'll have what I need. Kinda like the frosting on your birthday cake, for comparison purposes.

EDIT 3: I'm doing that too. One such skill that I already decided on is a literal "shoopwave"... and yes, it's an instant K.O.. (Extra +1 for anyone who gets the reference.)

@BreakerZero As you are looking for implementation suggestions, then I shall have to move this to JS Plugin Requests. Mechanics Design, as I already said, is not for implementation ideas, and it should be engine neutral.

I would also have to move it as it appears that you want suggestions only for your own specific project, rather than having a more broadly based discussion.

[mod]Moving this to JS Plugin Requests[/mod]

Which it certainly did, @Kes. And the comments leading to here actually helped a lot.

Also, in regard to XP multiples you can scratch that part - Yanfly Enemy Level handles that as well.

EDIT: For boss battles I actually plan on having a new set of actors in that department for the most part, and for added simplicity I set up a troop event specifically for use in the second quest which detects the initial "victory royale" state and engages difficulty buff accordingly... AND made it as easy as copy/paste across all my foes to date.

EDIT 2: This can apply to practically ANY project of course. But y'all did your share in contributing to my implementation in the process.