Notably, if playing dragons that has "whenever it deals combat damage" effects, those double with double strike as well - But a lot of those effects have been changed to "when it attacks" instead
Frequently Asked Questions What makes Japanese Pokemon cards different from English ones
I could see a version of this deck running MDFCs but you'd need to be very clear that they don't trigger Riku, and it might be safer just to leave them out
These are also heavy removal colors, whether thats in the form of single-target removal like Vanishing Verse and Vindicate, or full-on wraths like Damnation, Wrath of God, or gold sweepers like Kaya's Wrath and Exterminatus
Not to mention how valuable it can be for finding cards that fill the final pieces of the mana curve that you just havent considered
In recent years, it has shown its age, with players well wise to the lures of the green mage