It may seem strange for Wyvern to skip Cold Embrace early on. You may get it on level 4 if you want , but the general idea is to establish dominance on early stages. While Cold Embrace is strong ability, you will need damage for what we are going to do

The first thing to do on lane is to zone enemy support with Arctic Burn (and maybe enemy core if possible, you can switch targets while Arctic Burn is active to maximize damage). It will help you to get early level 2 and get dominance on your lane. Later on you'll want to max it out first since it's your main ability for both offensive (damage, slow, attack range) and defensive (slow, attack range, unobstructed movement) moves early on.

Our main farming tool early (before maelstrom), as well as harassing tool on lane. On level 25 it becomes annoying 2sec duration stun and your main ability to spam in fights.

You will use it as a setup ability most of the time. You can use it in a teamfight to remove one of your enemies (especially with Solar/Orchid/Bloodthorn: you can use them to amplify damage on ult's taeget) and contiue fighting with advantage, or just catch opponents and keep them in place while your team is repositioning and gets ready to fight, much like Naga's Song.

+{s:value} % Arctic Burnin hidastusta : This whole build and strategy is built around Winter Wyvern's Arctic Burn, so making it even stronger will be more helpful than making lower cooldown on heal

Splinter Blast tainnuttaa {s:value} sekunniksi : Additional 2sec lockdown with 7 second cooldown seems way more strong than additional 1.5 seconds on the ability that is long enough already and has 80 seconds cooldown

The first thing you want to do on your lane is to zone opponent away with Arctic Burn, get as much lasthits as possible and get early Boots for yourself. Wyvern is pretty slow hero, so this additional mobility early on is crusual for both your attack and defence.

~27 min Increasing our attack range drastically, as well as making our attack animation faster and removing arctiv burn stack limit is that strong so the whole idea of core Winter Wyvern was born out of it. Altho, you can't get it straight away since you need some kind of mobility item, mana regen item, attack speed item and all this while establishing dominance on the map.

Good item to increase attack speed drastically for a short period when you really need it. Works well when you have a mana item, Mjolnir and Aghs

Additional mobility/save with a higher potential than Lance early on

~19-22 min ALTERNATIVE: Power Treads

ALTERNATIVE: Boots of Travel

...but BKB is usually better choice against lockdown than Linkens

Huge mana regen and damage boost. Active ability has pretty good synergy with Winter's Curse (you just need to use it on the ult's target at a proper time to maximize damage output), but the main reason to pick it up is great passive stats that give us everything our hero needs

Continuing the theme of mana regen and int items, Scythe is the great addition, that also gives a good utility as well with its active.

Natural upgrade to Force Staff. Allowes us to get better position and zone opponents from miles away

Cheap offensive option if you want to get more damage, but don't really want to delay the game too much and won't be able to get top-tier alternatives

Mostly needed to purge Ghost form. Altho, it can work in combination with blink or Winter's Curse (use it right at the end of your ultimate, so enemy won't be able to dodge it)

OK-ish choice if you need armor. It's not really good item for core Wyvern since you need to get other stuff first, and when it comes to Shivas, you will usually be attacking from too far away for it to get benefit from it (as well as AC)

If you're still successfully winning your lane, but not sure about being able to finish in first 5-10 minutes, you can get Midas after Force Staff, so you'll be able to keep up later on. Altho, you already farm pretty quickly with Mjolnir and you don't want to spend 2k gold on an item that doesn't help you in fights.

Relatively cheap upgrade with huge damage boost (from attack speed and active ability)

OK-ish item to get if you're being locked down a bit too much or playing againstDoom

Agressive positioning solution, helps with better positioning for your ults (and future Hex)