Pet is used for very short moments. The stigma build used is Spirit Bundling one, which is a buff that make ur spirit disappear if used (and removes the buff if u summon a spirit).
Stigma for PvE: Infernal Blight, Magic Implosion, Infernal Pain, Cyclone of Wrath, Wilderness Rage, Curse of Magic Power, Summon Cyclone Servant, Command: Wall of Protection and last one whatever.. I use Enmity Swap.
For PvP u can just put Earth Protection, Shackle of Vulnerability instead. In some cases Withering Gloom or Cloaking Word may be useful, but depends where u go.
Pve I use Attack Power, Additional Dmg and AoE effect as Runes.
Odians i think the best way would be having 4x Reds with each skill, 1x Glowing Blue with Sandblaster and 1x Green with Backdraft, but also 4x Red + 2x Blue is fine or 3x Reds, 2x Blues and 1xGreen (which Im using atm)
The most important ones are Erosion/Magic Explosion/Elemental Smash, which are all Red Skills.
Glowing Green is useless for pve, that's why i use normal odian with good skill.
U may want Green with Stone Skin for PvP. Stealth given from Green glowing may be useful for openworld, but meh. Anyway I keep an earring to switch if i want to use the green glowing.