[quote name='panda911']What's the purple swirl elemental?[/QUOTE]
I've heard it drains health and shields but I've never noticed anything that dramatic myself. I'll have to test it later.
And what are synergy mods?
They unlock extra perks on weapons associated with a particular synergy. The number next to the synergy perk is the required number of equipped related mods necessary to activate said perk.
[quote name='Example']
LOL SPECIAL N00b CANNON
Synergy: Troll Extraordinaire
[1] -15% Grammar, +8% Annoyance while rolling/crouching
[2] +751 Damage Reduction when teabagging incapacitated allies
[3] +420 Melee Damage, 30% Melee strike speed at critical health
[4] +25 Health Regen, 35% Explosive DMG while jumping or under fire[/QUOTE]
All of those perks are nothing more than flavor text until you've modded a "Troll Extraordinaire" scope, barrel, mag or stock into the weapon to activate one. The perks remain active until the mods are removed so if you want them all you've got to slot in the max. You can try your luck by finding them out in the world or buying caches from vendors for a random chance of getting something decent.
If you're gunning for better odds with a specific type however you'll have to earn company reputation to buy those caches which can only earned through the Contract system. I'm pretty sure it unlocks for players around 250+ EGO.