User blog comment:GreenMoriyama/Izo, the Blizzard Prince/@comment-1330314-20160405115322

I really should have posted feedback earlier, particularly since I saw the first iterations of Izo's kit. You've put a lot of love into your champion, and it's always amazing to see champion concepts get developed and fleshed out over time.

Even though ice has been explored in many different ways with League's champions, you've still managed to take the theme and bring something new to the table. There are some features of Izo's kit I like, especially Glacial Spire, but I also feel there are some other issues, both big and small, that are holding him back. Some thoughts:
 * Frozen Edge looks like a fine passive. The AP ratio on the slow looks a tad high (you'd go to 100% slows and over at 750 AP upwards), and the cooldown is probably also a bit too high, but that's nitpicking numbers on a custom champion concept.
 * Crushing Bolverk looks a little out of place on Izo. It's basically a ranged autoattack, except it a) deals physical damage with a reduced AD scaling for some reason, on a champion who otherwise should be building AP, b) extends Frozen Edge's duration, despite the more natural use for it being the initial application, c) heals him by hitting minions, which isn't something you'd normally want to do unless you absolutely want your champion to last longer in lane, and d) resets Izo's autoattack timer despite already counting as a pseudo-autoattack reset. I feel you should probably redo this ability, as it currently looks fairly muddled and out of sync with the rest of his kit.
 * Frosted Coating providing shielding and a slow is appropriate on an ice-themed bruiser, but I think the slow is sort of backwards: shields generally incentivize opponents to attack them usually by providing buffs or debuffs until broken, but this particular shield discourages enemies from hitting Izo, which risks leading to lose-lose situations for his opponents. A likely better implementation would be to have Frosted Coating give Izo better CC capabilities while the shield holds, for example by having his own basic attacks reduce Frosted Edge's cooldown against targets or even grounding nearby enemies.
 * Glacial Spire looks fantastic. No complaints here.
 * Field of Rime looks fairly underwhelming. The slow is minuscule and redundant in comparison to Izo's passive, and Hoarfrost, which looks like a one-time effect, doesn't really add much to his contributions. I think you could do a lot more with this. One potential alternative, for example, could be to turn Field of Rime into a sort of ice skating rink that would modify the movement of enemies within, giving them turning speed and momentum akin to sliding on ice that would hinder their movement.

My main criticism for Izo is that most of his effects boil down to different slows, and so it feels like there's a lot of untapped CC potential to his kit, as well as a lot of redundancy. However, you have a strong, consistent thematic for your champion and a lot of flavor. Your concept is very strong overall, and while you should probably change a few more things in your kit, it's already well-polished.