What is the earliest CoC can come online, which Ascendancy, weapon and trigger skill?

Cyclone

[The Rainbow CoC] - Eternity Shroud Spectral Throw CoC Eye of Winter

3.15/3.16 Hit Scourge Arrow 8 Ballista Totem

SST CoC Ice Spear meme build

[3.15] Martyr of Innocence Vengeance Gladiator (14:45)

All You Need Is A Heartbeat? Ice Shot + Ice Shot Focused Ballista

Power Siphon Miner (Trickster)

[3.15] Shockwave Cyclone Build | Occultist | Expedition | Path of Exile 3.15

3.15 The Agnostic CWC Firestorm

Eternity Shroud Spectral Throw CoC Eye of Winter (aka The Rainbow CoC) vs The Maven