League of Legends (LoL) Question: Devourer Stacks.

It really depends a lot on how many stacks you get from team fights. Keep in mind 15 stacks will make the on-hit proc deal the same amount of damage as the AD you get from Enchantment: Warrior, so that's a good milestone to hit. I wouldn't worry too much about specific numbers because some games you can't just sit around farming your jungle if your team is losing or needs pressure.

By the way I would recommend Enchantment: Warrior on all the champions that you tagged. They have good AD scalings, and even though Aatrox and Jax have good autoattack steroids, they need the early game boost from Warrior to be effective.

Devourer is an enchantment for auto-attack dominant hard-clear junglers, someone who is lackluster on ganking but can farm like few else, Shyvana being a great example. Her dominant clear speeds along with auto-attack Q cdr and ult fury-building makes her a top candidate for Devourer. Tryndamere and Diana are also good picks for this due to their good clears early (especially if you pick up Statikk Shiv as a second item on tryndamere) and attack-speed reliant sustain in Trynda's case. You should be able to get the enchantment on your third back, depending on if you need to gank, if that gank is successful, and which champion you are using. Diana might get it a few after due to her somewhat weaker sustain and clear, especially if you have lackluster attack speed masteries, a must-have on her. If you get it third or fourth back, 50 stacks at 20 mins should be a goal, albeit with anything slower than shyv's clear or trynda's sustain it would be a struggle. On most AS/AD questions, I would recommend going with the AD, even after the Warrior enchant's 45-to-40 nerf. Devourer creates a commitment to farming, and farming hard, to be worth the money invested in it. It stands as a situational pick in most circumstances.