1: if I win after playing Study the Natural World can I choose no ring effects.

2: if I win as the attacked and my opponent plays display of power do they get all the ring effects, one of the ring effects or what?

3: if attacking toshi ranbo which element would it be considered.

7 minutes ago, Bayushi Shunsuke said:

1: if I win after playing Study the Natural World can I choose no ring effects.

You may choose no ring effects.

7 minutes ago, Bayushi Shunsuke said:

2: if I win as the attacked and my opponent plays display of power do they get all the ring effects, one of the ring effects or what?

Your opponent gets the ring effects of their choice, same as when Kaede is attacking and gets Display-of-Power’ed.
Because Study the Natural World instructs the attacking player to resolve the contested ring’s effects when they win the conflict (during step 3.2.3) separately from the framework resolution of one of the ring’s effects (during step 3.2.6), Display of Power does not prevent the “you may resolve each of the contested ring’s effects” delayed effect but it does prevent the framework ring effect during 3.2.6 (which will only be of a single element of the defending player’s choice, thanks to Display of Power).

7 minutes ago, Bayushi Shunsuke said:

3: if attacking toshi ranbo which element would it be considered.

If you are attacking Toshi Ranbo, the contested ring gains all five elements.

[Tyler Parrott, May 20 2020]

(1) Is Study the Natural World a replacement effect, firing at 3.2.3 and replacing the normal choosing the element step of resolving a ring? It looks like it should be but the wording doesn't appear to match.

(2) If I play Study and then trigger Kami Unleashed, do I choose one element or resolve all? Study references the player, unlike Kaede, but is the replacement effect in effect during the Kami trigger?

Just now, Bayushi Shunsuke said:

(1) Is Study the Natural World a replacement effect, firing at 3.2.3 and replacing the normal choosing the element step of resolving a ring? It looks like it should be but the wording doesn't appear to match.

Study the Natural World does two things, neither of which is a replacement effect:
1) It adds the corresponding elements to the contested ring immediately.
2) It creates a delayed effect that occurs during step 3.2.3. If you win the conflict, you resolve the contested ring’s elemental effects (all of them). This is separate from resolving ring effects during 3.2.6, meaning you can resolve one of the elements twice (you resolve all of the elements during 3.2.3 due to the delayed effect and one of your choice during 3.2.6 per the normal framework effects).

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(2) If I play Study and then trigger Kami Unleashed, do I choose one element or resolve all? Study references the player, unlike Kaede, but is the replacement effect in effect during the Kami trigger?

If you activate Kami Unleashed while Study the Natural World is active, you choose a single element, as when instructed to resolve the effect of a multi-element ring you choose one instead of resolving all of them (RRG page 17).

[Tyler Parrott, May 21 2020]

Since there's no duration specified in the text, is the intention of this card that the ring gains the elements forever, or just until the end of the conflict?

Just now, Bayushi Shunsuke said:

Since there's no duration specified in the text, is the intention of this card that the ring gains the elements forever, or just until the end of the conflict?

This one only lasts until the end of the conflict.

[Tyler Parrott, May 11 2020]