Random Rainbow Bullshit Go! (EDH / Commander) [Révision 8]

Get domain fast via Prismatic Omen, Dryad of the Ilysian Grove, Nylea's Presence, Leyline of the Guildpact, or with all the fetches. Use Jegantha and 5 lands to play two powerful spells a turn. Win (?)
This deck aims to chain tutors (i.e. tutor for conflux to tutor for tiamat to tutor for combos) in order to amass a huge board of hard-to-kill threats.

Leyline of the Guildpact + Iridian Maelstrom = In Garruk's Wake
Leyline of the Guildpact + Scion of Draco = Shitty Akroma's Memorial
Leyline of the Guildpact + Last Stand = Island effect is not great, but sometimes the damage and lifegain is good in a pinch.

Conflux Targets:
Leyline of the Guildpact - almost always grab Leyline because lots of the cards in this deck are more powerful with it.
Chakram Retriever/Jeskai Ascendancy - use with Jegantha and Jodah/Fist of Suns to play all the cards from your hand.
Tiamat - Tutor 5 more cards. Insanely good in this deck. Consider Congregation at Dawn instead if you already have Tiamat.
Jodah, Archmage Eternal - use with Jegantha and Chakram Retriever/Jeskai Ascendancy to play all the cards from your hand.
Heroic Intervention/Teferi's Protection/Rhythm of the Wild - Protect your board for the turn where you combo.

Tiamat Targets:
Scion of Draco - Very good with Leyline of the Guildpact.
Kyodai, Soul of Kamigawa - Another instant speed protection piece, like Heroic Intervention or Teferi's Protection.
Moonveil Regent - Once you have the infinite assembled, this lets you go even further beyond. Eventually play Najeela, the Blade-Blossom for the win.
Two-Headed Hellkite, O-Kagachi, Vengeful Kami, Niv-Mizzet, Guildpact, Niv-Mizzet Reborn - For use with Moonveil Regent.

Congregation at Dawn targets:
Tiamat, Jodah, Archmage Eternal, Chakram Retriever

Diabolic Revelation targets:
Tiamat, Jodah, Archmage Eternal, Chakram Retriever, Bringer of the Black Dawn, Congregation at Dawn.