Riku of Two Reflections — ruling 1

Each time the first ability triggers, you can pay {U}{R} only one time to get one copy of the spell. Each time the second ability triggers, you can pay {G}{U} only one time to get one token.

Riku of Two Reflections — ruling 2

If the spell that caused Riku's first ability to trigger has left the stack by the time the ability resolves, you can still pay {U}{R}. If you do, you'll copy the spell as it last existed on the stack.

Riku of Two Reflections — ruling 3

Riku's first ability triggers whenever you cast any instant or sorcery spell, regardless of whether that spell has targets.

Riku of Two Reflections — ruling 4

If the copied spell has {X} in its mana cost, the value of X is copied.

Riku of Two Reflections — ruling 5

If the copied spell is modal (that is, it says “Choose one —” or the like), the copy has the same mode as the original spell. You can't choose a different one.

Riku of Two Reflections — ruling 6

You can't pay any additional costs for the copy. However, effects based on any additional costs paid for the original spell are copied as though those same costs were paid for the copy. Notably, if the original spell was kicked (or kicked a certain number of times), the copy will also be kicked (or kicked that many times).

Riku of Two Reflections — ruling 7

If the creature that caused Riku's second ability to trigger has already left the battlefield by the time the ability resolves, you can still pay {G}{U}. If you do, you'll still put a token onto the battlefield. That token has the copiable values of the characteristics of that creature as it last existed on the battlefield.

Riku of Two Reflections — ruling 8

As the token is created, it checks the printed values of the creature it's copying, as well as any copy effects that have been applied to it.

Riku of Two Reflections : règles, fonctionnement et interactions (MTG)

Riku of Two Reflections is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Whenever you cast an instant or sorcery spell, you may pay . If you do, copy that spell. You may choose new targets for the copy. Whenever another nontoken creature you control enters, you may pay . If you do, create a token that's a copy of that creature.

How it works : Riku of Two Reflections

Original English text — Wizards of the Coast / Scryfall

#1September 22, 2011· Wizards of the Coast
Each time the first ability triggers, you can pay only one time to get one copy of the spell. Each time the second ability triggers, you can pay only one time to get one token.
Card named in this ruling
Copy
#2September 22, 2011· Wizards of the Coast
If the spell that caused Riku's first ability to trigger has left the stack by the time the ability resolves, you can still pay . If you do, you'll copy the spell as it last existed on the stack.
Card named in this ruling
Copy
#3September 22, 2011· Wizards of the Coast
Riku's first ability triggers whenever you cast any instant or sorcery spell, regardless of whether that spell has targets.
No other card is named in this ruling.
#4September 22, 2011· Wizards of the Coast
If the copied spell has in its mana cost, the value of X is copied.
No other card is named in this ruling.
#5September 22, 2011· Wizards of the Coast
If the copied spell is modal (that is, it says “Choose one —” or the like), the copy has the same mode as the original spell. You can't choose a different one.
Card named in this ruling
Copy
#6September 22, 2011· Wizards of the Coast
You can't pay any additional costs for the copy. However, effects based on any additional costs paid for the original spell are copied as though those same costs were paid for the copy. Notably, if the original spell was kicked (or kicked a certain number of times), the copy will also be kicked (or kicked that many times).
Card named in this ruling
Copy
#7September 22, 2011· Wizards of the Coast
If the creature that caused Riku's second ability to trigger has already left the battlefield by the time the ability resolves, you can still pay . If you do, you'll still put a token onto the battlefield. That token has the copiable values of the characteristics of that creature as it last existed on the battlefield.
No other card is named in this ruling.
#8September 22, 2011· Wizards of the Coast
As the token is created, it checks the printed values of the creature it's copying, as well as any copy effects that have been applied to it.
Card named in this ruling
Copy
#9September 22, 2011· Wizards of the Coast
The copiable values of the token's characteristics are the same as the copiable values of the characteristics of the creature it's copying.
Card named in this ruling
Copy
#10September 22, 2011· Wizards of the Coast
If the creature had in its mana cost, X must be 0. Note this is different from an found in the mana cost of a copied spell.
No other card is named in this ruling.