This is a much more contained iteration of Notion Thief being less mana, fewer colours, and more robust. Sure, you get treasure instead of cards with this but it is mostly about denying the draw, any perk on top of that is just gravy. You can hold this for the got ya moments or you can just flop it out and have it be a bit of a Narset, Parter of Veils that attacks. So a hatebear or a great value Spell Swindle. Both fine lines/modes. You really don't need much out of this for it to be pretty devastating and the floor is decent giving this a pretty reasonable chance in cube. Good tribes too giving it yet more chances of action if it doesn't cut it in drafting cube.
Sakashima's Will 0
Bad Control Magic or one of the most situational effects of all time. This isn't unplayable without commanders but it is a long way from good. The frequency that the second mode is useful will be so low you might as well play better Control Magic effects instead of this.
Sakashima's Protege 1
This seems doubly random. Cascade itself and then potentially having to copy whatever you get from that or wait until your opponent makes something worth having. The high rolls are obviously high with this but the floor is bad, as is the average performance. Mostly this sits in hand not doing much of anything.
Sakashima of a Thousand Faces 1
Do I want Mirror Gallery on a Clone? We can break that down into two questions, do I want Mirror Gallery and do I want Clone. When the answer to both of those is no then we have a solid answer for the original question. I am sure this has uses (perhaps even beyond Gyruda) and has a fine power level but not what we are looking for cube wise, especially when we have Spark Double already.
Coercive Recruiter 2
Another Zealous Conscripts but worse. Playable but hardly desirable. Threaten is situational at best when used conventionally. Used with Kikki Jikki it is fine but not like we are short on things to abuse that way.
Reyav, Master Smith 2
Powerful in the right deck but super narrow and not even all that unique. I can find plenty of good ways to double strike up dorks and so Reyav is deck padding, good padding but still padding.
Kangee, Sky Warden 0
Powerful but narrow and too far up the curve to be the kind of synergy card you are excited about. It needing to attack to aggressively pump takes most of the punch out of this one.
Gilanra, Caller of Wirewood 1
Nice to have a clean ramping partner commander. In normal 1v1 this is a three mana Llanowar Elf that might draw you a card here and there if you are lucky. Llanowar Visionary is orders of magnitude better. As are Llanowar Elf and Elvish Visionary for that matter. Simply put, your six drops should be getting you most of the way to winning and so you shouldn't need extra cards with them.
Dawnglade Regent 1
Very pricey card for very little threat. This is more value and protection than it is a win condition and that mostly rules it out for cube uses.
Ingenuity Engine 1
I like the utility of this card but I do not like the 7 mana price tag regardless of the cascade. I am simply not sure where you could play this usefully. You need things like Divining Top to ensure a good hit and even then the card is only fair rather than good or particularly powerful.
Akroma's Will 1
Without controlling a commander this isn't packing enough punch to merit the high cost and situational nature of the card. Wrath protection is nice but at four mana you can do a lot better. It can force through damage or increase the damage of an attack too but the cost is just too high for the returns. Brave the Elements laughs at this. Assault Formation won't return it's calls. Don't even ask about the Anthems and planeswalkers...
Akroma, Vision of Ixidor 1
Overcost and rather sitiational. Sure, this can be one hell of an Overrun effect backed up by a big scary flier. Without the right kind of dorks in play this is a hard fail to the Doom Blade test and is just a slow vulnerable fatty.
Pride of the Perfect 1
Quite a powerful Anthem for elves but elves have Overrun effects a plenty and don't need to step outside of green to access them. Being a little off theme, off colour and not an elf make this look like it isn't getting play despite being perfectly decent on power level.
Feast of Succession 1
Cool looking card that works well with itself. It helps you keep monarch and does two controlly things simultaneously. Sadly it is a six mana Languish that fails to kill everything and probably loses you the game if they have a haste dork, survivor, or just a manland in order to steal the monarch from you.
Mira, Thorn of the Glade 2
Cheap and useful but rather undone by costing a mana in order to turn on the trigger. You don't want to be keeping up mana and so this will give your opponent plenty of windows to shut off this value engine. Certainly a playable card but probably more in an aristocrats style deck that happens to have a high elf count rather than a tribal elf build.
Kwain, Itinerant Meddler 1
I guess this has some potential uses when you are locking people down card draw or trying to force draws for whatever reason. Even so it is a bit of a risk as it isn't helping you all that much when you don't have your other synergy parts.