[Slydria]

Seeker Flames leave behind their battle rings when they die.

[Neus]

Do any other associates (like Youkai or Engineer bots) or is it just them?

[Slydria]

Yes, after testing, both Youkai and Engineer bots leave their battle rings behind when they die too.

[Neus]

What about when the Youkai are unsummoned manually?

[Soapy]

Works fine when they're unsummoned.

[Trexmaster]

To add, Butterfly Illusions also leave behind their rings after death -and- if they're unsummoned manually.

[catabur]

With great power comes great responsibility.
(too bad I'm not responsible)

[MegaBlues]

[Neus]

This should be corrected.