Vortices can now fight back

[chaosvolt]

Summary

SUMMARY: Balance "Vortex monsters no longer harmless despite being aggressive, make vortices and mutants friendly"

Purpose of change

This effectively ports over some changes to a vanilla monster from Arcana and Magic Items mod with some changes, to make one monster that is notably hostile but harmless (due to getting a special attack it used to use instead of normal attacks, long before my time it seems) actually do something.

Describe the solution

1. Defined monster faction JSON for mutant and vortex faction, made mutually friendly as mine spirals are populate mainly by those two factions.
2. Set it so vortices actually have the ability to fight back. Gave them some basic melee damage (in line with some Arcana alterations to vanilla monsters I plan to rebalance and port over in the future), with a set amount of bonus electric damage.
3. Set it so that vortices aren't aggressive by default, but become hostile via stalking behavior or harming them, along with a placate trigger. This makes them start off behaving similar to the current status quo (hostile but harmless so they just meander), but pull out a nasty surprise when provoked, but can be calmed afterward as well.
4. Gave them ability to see, just short enough a range that they'll be likely to actually respond to the player's actions.

Describe alternatives you've considered

1. Figuring out some way to hack together an area_push spell that'll do something like what the ancient dummied-out vortex special attack used to do.
2. Giving them the SMASH attack and seeing if it can be flavored as a targeted gust of wind.
3. Giving them the stare attack once the nether attention require is merged.
4. Figuring out where else to spawn vortices. I have plans for more use of cult monsters and possibly wraiths, those being currently underused, but where else would be a good vanilla use for these things...

Testing

1. Load-tested in compiled test build.
2. Went to a spiral mine, observed that vortices and local mutants weren't infighting.
3. Poked about with a vortex, got it to attack me, did indeed hurt.
4. Found that getting badly injured would sometimes stop the beatings.

So, a thing this lead me to discover: far as I can tell, whatever code is involved in processing PLAYER_WEAK as a placate trigger, it doesn't kick in noticeably unless all of your limbs are very badly damaged. If by sheer chance most of the damage goes disproportionately to your torso or head, despite player::hp_percentage weighting them higher, they likely won't even notice how close to dead you are until it's too late.

This is most easily tested with giant rattlesnakes, as other than that there are very few monsters have have PLAYER_WEAK as a placate trigger, and most of them are more likely to flee than turn hostile.

Additional context