I'm going to shamelessly quote myself from another forum (not MTGS) for a post which didn't get much feedback. I'm hoping you guys might be able to help me figure this out.
I think maybe a better example than Siege Rhino/Doran would be Mantis Rider/Jeskai Ascendancy - the Ascendancy directs your deckbuilding a lot more than the Mantis Rider would, it's harder to kill, and it can be searched up more easily due to Enlightened Tutor.
Let me know what you think! I've lurked here a little and maybe this is a bit much for a first post, but I would welcome all feedback/discussion.
I have some thoughts I want to type up on three colour cards in cube.
I'm going to preface this by saying that my design philosophy with regard to cube is that you want as few "narrow" cards as possible that only go in one deck - stuff like storm enablers like Seething Song and cards which require three or more colours of mana - as in the majority of drafts they're going to end up as 15th picks rotting in someone's sideboard.
That said, on the back of Khans there are a lot of powerful new three colour cards and I'm thinking about maybe giving a few (specifically one of each three colour combination) of them a shot. However, for me, it's not enough for these cards to be powerful; the cube is already full of efficient creatures, and the trade-off of having three colour cards which are only going to make a maindeck in one out of three drafts or whatever means that simply being powerful is not enough. So for a three colour card to be a consideration, it has to both be powerful and have a unique or interesting effect that I can't find elsewhere.
For example, take Siege Rhino. There's no doubt that it is a very strong card and probably in a vacuum the best option for Abzan. However, I don't think it's enough better than similar cards like Bloodbraid Elf or Restoration Angel to warrant its inclusion. I think for this reason a better Abzan card is Doran the Siege Tower, as taking him early allows you to craft your deck around him and completely changes the draft dynamic. I figure, if you're going to include cards which are made narrow by virtue of their colours then you may as well have narrow effects whilst you're doing so.
That said, this opens up some other issues. Putting Doran in your cube is like making a promise to your players that there will be enough cards in the draft pool that support him to make a "Doran deck", and currently at least I'm not sure there are that many creatures in Abzan colours with significantly higher toughness than power that are cubeable. Courser of Kruphix is the only one that springs to mind, although of course Restoration Angel, Tarmogoyf, Noble Hierarch etc all benefit as well.
The second issue is that what if you build a Doran deck and only draw him in half your games or even none at all? You have a collection of big butts that don't really do anything. Doran is in a pretty good spot by virtue of being a green creature, so he's pretty easy to find, but this problem extends to the other three colour cards as well.
My question therefore is can you assist me in finding three colour cards which fit the above criteria? So far, I think Doran is a good choice for Abzan, Jeskai Ascendancy for Jeskai and possibly Sidisi for Sultai, but I'm coming up pretty short for the others. Even those would require a reasonable amount of re-jigging my cube so that their themes are supported.
Just to be clear, cards like Wild Nacatl and Taisgur are classed as single coloured in my cube since you don't need three colours to play them.
I'm going to finish by saying Sphinx of the Steel Wind (along with Siege Rhino) is what prompted this post since I think it has no place in any cube. I would be interested to hear counterarguments though.
For reference, here's my current list: http://cubetutor.com/viewcube/6050
It's not really updated to Theros as I generally wait for standard rotation to pick stuff up cheap, but there are some random cards I've opened in limited from the last two blocks.
I think maybe a better example than Siege Rhino/Doran would be Mantis Rider/Jeskai Ascendancy - the Ascendancy directs your deckbuilding a lot more than the Mantis Rider would, it's harder to kill, and it can be searched up more easily due to Enlightened Tutor.
Let me know what you think! I've lurked here a little and maybe this is a bit much for a first post, but I would welcome all feedback/discussion.