Looks pretty solid; I can't really add much. I am a little surprised not to see Kiki-Jiki and Palinchron in here. Are they to slow / color intensive?

There is no synergy with Palinchron and i want to play as few expensive cards as possible, so i don't think i would cut any of my current cards for it. Kiki-Jiki, Mirror Breaker would certainly be really powerful, but i don't want use him to combo kill (just personal preference) and also the current manabase would have big trouble to support it. If you want to build the most powerful version of this deck, Kiki Jiki, Imperial Recruiter, Deadeye Navigator and Palinchron are almost certainly all in there, but because of budget and fun reasons i don't play them.

Oh, gotcha then. I totally get building more for budget and fun than outright power. I just wasn't sure where you stood on the issue -- sometimes I assume a build is all-in on winning at all costs when I see a strong tutor engine. I need to check that!

Anyway, it also occurred to me: how about Hibernation's End or Yisan, the Wanderer Bard as back-up Pods?

Well i definitly try to make my deck competitive and synergystic, i just don't want to get those "Oops you are all dead to my combo"-situations if i can avoid it. I'd rather have a game over many, many turns where everybody does his thing and eventually only one is left standing. Hibernation's End and Yisan, the Wanderer Bard are fun, but also too slow for what i am trying to do. It would take forever to find a card like Acidic Slime or Resolute Archangel with those, but Birthing Pod gives me access to them very quickly.

Oh yeah, it's definitely a spectrum -- your deck looks really tuned, which is why I immediately spouted off with cutthroat combo elements. It seems that you build a lot like me, trying to win within certain arbitrary limitations (theme, pet cards, social regards, ect). I had a very similar Horde deck before, but ended up scrapping it because of complaints over some infinite Reveillark combos therein.

I was toying with the idea of bringing something like the deck back recently, mostly just because these five-color builds end up being compilations of all kinds of cards I like that must be played... together! I guess I'll have to find a way to avoid including any sort of loops, even though I just like stuff like Reveillark and Karmic Guide at face value, regardless of shenanigans. I wonder if you encounter such difficulties?

When i initially built the deck, i didn't intent to include any real combos or loops at all, just lots of exciting and powerful cards, but with Reveillark in the deck you more or less stumble into it anyway (and cutting that card from my deck is not really up for discussion). However, Reveillark-loops involve 3-4 creatures and require the graveyard, so it's definitely possible to disrupt that on multiple axes. I am okay with having that in my deck, but i consciously try to not always play for infinite Reveillark recursion. The deck is very capable of playing and winning in a more fair way (depending on how "fair" you consider using Birthing Pod multiple times each turn) and i find it highly rewarding to figure out the correct lines of play when you have access to most of the creatures in your deck at any given time. Occasionally i go for the combo kill, but in return i sometimes die on the spot to an unexpected Craterhoof Behemoth, Insurrection or Ugin, the Spirit Dragon from the opposition, which is all okay as long as it happens in the right dosages and doesn't get repetitive and boring.
So, i guess my personal verdict is: A little bit of "back-up combo" is okay, but i prefer no to play a card like Palinchron because it is just too likely to cause loops to happen when i don't even want to combo.

I can't bring myself to understand how the Phantasmal Image, Sun Titan, and Animate Dead combo works.

That's simply because it doesn't work, my bad. It requires a second effect like Animate Dead to form a loop, so Dance of the Dead or Necromancy are possible ways to make it work.

1) Assume we start with Animate Dead, Dance of the Dead and Phantasmal Image in the graveyard.
2) Titan enters the battlefield, its trigger targets Image.
3) Copy Titan, trigger targets Animate Dead.
4) Sacrifice the original (or copied) Titan.
5) Animate Dead comes into play, returns the Titan (or Image).
6) Now repeat steps 3)-5) using Dance of the Dead in place of Animate Dead. That's the loop, you just have to alternate between the two enchantments as one has to be in play when the other becomes target of an ability.

Actually, once you have two Animate Dead type effects in the deck, you can also form a similar loop using Body Double in combination with Sun Titan and the enchantments.

Thanks a lot for pointing that out, i will update the primer soon.