Agree with Zanta fully. League, like all MOBA's, require understanding. There's not just "Do it", there has to be a "Why'd you do it?".
Okay, less of my kissing up to Zanta and onto more of a personal perspective.
I played Sejuani a lot. A -lot-, my favorite jungler even.

-Barrier: Why? Sejuani is decently tanky by herself, and if you build correctly Barrier will be useless by minute 15, honestly Flash (to me) is useful 100% of the game.

-Masteries: Wrong, but Zanta cleared that one up, also, you showed it twice. Redundancy annoys me, and if it annoys me, it must annoy at least one other person here.

-Rank: You're diamond, that's cute. That doesn't prove champion proficency. I'm an ex-Silver and a now lowly Bronze and I can still play a better Sejuani/Evelynn than most of my superior ranks. Show us how many games you won WITH Sejuani and WITH the build.

-Lore: Has no place in a build unless you modify it for a joke/etc. ( I still don't like them, but I've seen some clever modifications). If I want to read the lore I'll go on League and read it there, not spend time on the guide reading it.

-Ghost: Ghost fanatics only? This made me laugh. Sejuani isn't the fastest champion around, and while it -is- an optional choice, it's not a bad one.

-Runepage: No information as to what the runes are, what the quints are, etc. I can see the final product but don't you think your readers shouldn't be guessing?

-Items: Why are the items seperate from the cheat sheet? Non-interactable on top of that.
"As you can see, I like to purchase " Ruby Crystal ". I love this item and its also cheap. Stacking these will give you a toughness similar to Warmog's Armor." No. Just no. No stacking Rubies.

-Match-ups: .... We both know you dropped the ball on that one.

I'm tired of this. -1. Better luck next time.

Unyielding / Block useless in jungle. Defender / Legendary Armor useless in general.
You just wrote 1 single sentence for every champion... Let's pretend I'm a new player for a moment , okay?
"Okay so i take Barrier and Smite on every jungler. That guy will KS with his Ulti(who the **** is he and what the **** does his Ulti does), Good initiator (with what), She can use her ultimate perfectly( what ultimate), hard to catch (why), don't 1vs1 this guy (why? if i wanna 1vs1 him whatta gonna do) etc..