Notable Decisions:
Ramp-
Heartless Summing: Puts us 2 mana ahead for a slight disadvantage.
Farseek: 3 colors including Green, duh.
Axebane Guardian: survives HS, evolves Gyre Sage, provides multi-colored mana for Liching enemy creatures, synergy with Fog Bank.
Gyre Sage: survives HS, potential to grow (most games see her at ~2 counters), growth offsets HS.
Beatdown-
Bloodgift Demon: 4/3 flier turn 3? extra card at minimal cost? Not exactly the strongest body, but it does apply pressure/advantage
Thragtusk: 4/2+5 life turn 3. Not exactly a strong attacker, but triggers Gyre Sage twice. Happily tradable (especially with recursion). Still trades (or dies) with most creatures that kill normal tusks.
Consuming Abberation: Other considerations were Primordial Hydra and Nimbus Swimmer. Abberation grows like Primordial, but in doing so has an alternative win con. I've seen the mill effect hit (not common by any means) 17 against an aggro deck in 1 shot. Lacks the evasion of the other 2, but will never costs more than 5 mana (3 with HS).
Mikaeus: Very helpful here. Decent body, mediocre evasion. Offsets HS on almost everything. Undying really helps against field wipes, doubles up on ETB triggers. Added bonus, human removal in a format full of RG Shamans
Utility -
Havengul Lich: HS enables some fun interplay. Not as strong as with Perilous Myr, but has applications. Being able to continue casting from the grave triggers independant ETB effects as well as Consuming Abberation. Particularly useful if timed well against Humanimator to steal some key pieces.
Dinrova Horror: Bounce a PERMANENT, and discard a card on a fair body.
Evil Twin: Takes out Olivia, Geist, and all other scary legendaries. Also comes in as a copy of something you want more of, or something scary that needs to die next turn.
Deadeye Navigator: +Dinrova Horror = Repeatable land bouncing and hand attack. +Thragtusk = Significant stall for time/creature tokens. 2UU: Counter targeted removal on a creature you control.
Sideboard -
Curse of Echoes: Turns card advantage into card- and turns counter into counter counter.
Deathrite Shaman: Helpful vs Snapcaster and Reanimator decks. Survives HS, rarely ramps, does a lot of work in a game.
Dimir Charm: Counters combo spells, removes small creatures in aggro and in combo decks.
Golgari Charm: Regenerate for board wipes, enchantment removal isnt entirely wasted. Most importantly the -1/-1 mode is heavily underrated from testing experience.
Slum Reaper: Sorcery speed sacrifice effect for 1B? ~ok. Buyback 1 and turns into a 2 for 1 if mikaeus is out. Helps more with aggro.
Feedback appreciated.