One of the best advantages in MtG is being able to play multiple things in a single turn. That benefit is even greater when you don't have to pay mana costs. Welcome to the Deck that lets you play many spells off of one.
The concept of the Deck is to run Maelstrom Archangel trigger, Cascade, and Rashmi, Eternities Crafter trigger to essentially play a minimum of 3 cards for free(details below).
Let's talk about land first:
You will notice there are no basic or commonly seen dual lands here. No need. We're running a Five-Color Deck, so we need all the types we can produce. First off, given the opportunity, go on the draw, not the play. Why you ask? Gemstone Caverns. The effect is worth the exile of a card. If you are playing casual and get to look at your starting hand, and have none of the lands opening up, go ahead and go for the draw. We need as much of a head start as possible.
Next up is Reflecting Pool. This land not only comes in untapped, but if you have the Gemstone Caverns with a luck counter on it, or even a Vivid land(with or without a charge counter!) out, you get to produce any mana of any color. Birds of Paradise is also the best mana dork for this Deck style.
Now let's look at the spells.
Just to clarify how this Deck can potentially operate, let's talk hypothetical scenario.
You have Maelstrom Archangel, Rashmi, Eternities Crafter and
Maelstrom Nexus
on the battlefield. In hand, you have Emrakul, the Promised End. The key here is to not play anything on your first Main Phase and go straight to combat. Remember, Maelstrom Nexus and Rashmi only trigger on your first spell you cast(key word) each turn.
Skip first main phase, go to combat. Swing Maelstrom Archangel. Hopefully, deal damage to opponent. Trigger ability, free cast Emrakul. You didn't ETB Emrakul, remember. You cast her. So her ability will trigger. Next trigger is Maelstrom Nexus. Go ahead and cascade off Emrakul's mana cost(12 or less). That's anything else in the Deck. Hopefully you get a Planeswalker or Progenitus, but anything free is good, right? Cast your cascaded card. Next trigger on the stack is Rashmi, which is basically a mini-cascade. Reveal the top, and either cast it or put it in your hand.
Another thing is if you topdeck Temporal Mastery or Terminus and pay the miracle cost, you still get to cascade or Rashmi trigger off the actual converted mana cost of the card.
Jhoira of the Ghitu
allows you to early game set aside big cards like Progenitus, Emrakul or Planeswalker for a four turn free cast delay, while you work on getting Maelstrom Nexus and Rashmi out.
There you go.
Feedback and suggestions more than welcome!
Sideboard to come. Potential Deck searchers Diabolic Revelation and/or
Conflux