Bind Demon 20+ Can I keep unbinding and re-binding until get a specific aura?

You can go and hunt down the "same" demon in different games over and over until you get the right aura on it.
But sadly, you can't release and re-bind the same demon over and over to speed things up.

And yes, you can bind-kill.
Even quest mobs if they can be bound.
If you bind Heph for example, he drops his hammer instantly so you can smash your soul Stone while he protects you now instead of his forge.

fredkid wrote: 14 hours ago

But, if after binding the demon, I unequip some +skill items (to make

Bind Demon level 19-) and then exit game, when I create a new game, do the binded demon keep the previous aura?

I think the answer would be yes...
But if it is no, I think we could manipulate the

Bind Demon level in order to remove the aura and give a fresh new one while exiting and recreating games

I actually had that same thought and ran a quick test earlier:
Dropped my bind to below 10, 10 with items. So with items, it adds extra fast. Nice and easy to judge by the mob speed.
Snatched a demon without extra fast at lvl 10. Got him extra fast as expected.
Unequipped some items to drop below 10.
Left and made a new game.
Still had an extra fast demon.

Mind you, I only ran that one test but it seems as though stats are locked in upon binding and don't actually re-adjust when joining a new game.
However, there is a chance - albeit relatively low - that this particular demon had a hidden 'extra fast' already. Didn't pay enough attention to the pre-bind run speed, only looked at the affixes. So this isn't a fully reliable test and I'd recommend still attempting your aura juggling with skill items to see if that works. Hidden affixes tend to be more rare but they do happen, such as my current Heph cursing everything in sight despite not being 'cursed'.

Can't bring myself to give up my current fana/curse Heph, now that I finally found him on ladder but generally, at some point, this should be tested properly. If it really does get locked in, there's something to be said for finding some specific demon binding gear to really tune up that servant, seeing how it could then be dropped right after.

Schnorki wrote: 11 hours ago

[..]
Can't bring myself to give up my current fana/curse Heph, now that I finally found him on ladder but generally, at some point, this should be tested properly.
[..]

Just for the sake of confirming, I gave this another go on single player (i.e. without losing my Heph ^^).

Used a random normal non-tz mob this time to be sure there are no hidden affixes. And looked more closely just to be triple-sure.
Binding with items (10+) gave a slow-poke mob extra fast as expected.
Dropping items after that (down to 7) and making a new game preserved the extra fast.
Holds true across multiple games.

The same thing is true going in reverse. Binding at 7, then equipping gear to 10+ and joining new games does not then add extra fast.

Tested this with both, 10 for extra fast and 20 for aura (going from <20 to 20+ doesn't add one).
Also tested with both, gear points and hard points.

So yes, seems stats (or at least affixes) are indeed locked in upon binding and not on new game.
As a result, if you level up and use your newly gained skill points to improve a bound demon, you may want to look into finding a new one as your current one won't be updated.
Similarly, if you want to take the time and put in the effort, there is then absolutely something to be said for demon-skill gear just for binding purposes.

Might be worth adding a note about this on the skill's page.

ShadowHeart wrote: 1 hour ago

Might be worth adding a note about this on the skill's page.

Added one.

fredkid wrote: 1 hour ago

Well... On ther other hand, this means that you can temporarily increase your

Bind Demon level (shrine, swap, etc...), just before the binding to gain extra an extra afiix, if your "regular level" is close to 5/10/15/20

Hence the "there is then absolutely something to be said for demon-skill gear just for binding purposes".

Given, I for one am far too lazy to deal with gear-switching even for something as rare as binding another demon but for those who enjoy doing so, go for it.