Sated Devourer [Explained]
Basically (and I'm stealing words from Meddler here) the extra proc is another basic auto attack that deals no base damage. The list below is by no means exhaustive and only lists some that could probably be seen.
What this does help (Any ability that applies on hit EVERY HIT): Devourer Magic Damage Fizz W Master Yi E Master Yi Passive BotRK Skarner Passive Nunu Passive
What this does nothing for (Things that apply on hit CONDITIONALLY): _All Sheen Proc Items Aatrox W (More on this at the bottom) _
The abilities that this enchantment will do NOTHING for are abilities that are applied on a single hit and then disappear. The only things that benefit from devourer are abilites that are applied all the time on-hit. Since Trinity Force Spellblade only lasts for 1 auto attack the second part of this does nothing.
*On Aatrox, his passive WILL NOT proc twice because of this, however it will proc twice as often because it procs every 3rd auto attack and this new 'phantom proc' counts as an auto attack towards the counter.