Originally Posted by IHelpPro
Good guide, but boots should be either ninja or mercury IMO. 40% duration reduction on stuns and fears is crucial in allowing you to continue autoattacking.
And this might be personal preference, but I go max shield at 9, with 1 level in stun and rest enrage. Shield seems much more useful in both farming and harassing.
Last thing, maybe consider Last Whisper vs armor stacking tanks.
Someone already mentioned the mercury treads as an improvement over berserkers, and I added it to the guide because you are correct.
As for shield vs stun as a harasser, stun is actually better if you go for damage, because it lets you get in a hit or two as well. the damage of stun and shield is almost identical, but since your item set is built to max your damage, getting one or two hits in does more damage then the stun does. If you are building an AP Sion then yes shield is the better harasser. Also the main point of getting the stun is so you can kill and chase, not to harass, though its good for that too.
One thing to note about harrassing with stun is that my runes give me 14% critical chance and 220% crit damage at level 1, so if I get a little lucky and crit, then my 1 hit after the stun can do 2 to 3 times as much damage as the stun or shield would. If I stun and crit most squishies will start running immediately cause that's about 300 to 400 damage at level 3 or 4.
As for last whisper, I've rarely seen anyone get enough armor that I needed it (most tanks stack health, not armor), however the extra attack speed and armor penetration would definitely be good on him, so ya, its a great item to consider, probably in place of the blood thirster or banshees veil, because I love critical strike too much to give it up with this build.