Skillorder:
[1]: Frostbite, [2&3]: Brilliance Aura, [4]: Crystal Nova, [5]: Brilliance Aura,
[6]: Frostbite, [7]: Brilliance Aura, [8&9]: Frostbite, [10&11]: Freezing Field, [12-14]: Crystal Nova, [15]: Stats, [16]: Freezing Field, [17-25]: Stats;
Startitems:
Chicken, 2x Tangoes of Essifation, 4x Ironwood Branches
Items: Observer Wards, 1-2 Bracers, Mekansm, try to get a Kelen's Dagger+ Black King Bar. Get Vladimir's Offering if needed. Get Necronomicon if needed. Get Power treads. Don't forget to buy Scrolls of Town Portal. Your normal equipment in a competitive game (at the 35 minute mark for example): Boots of Speed (Or Power treads if you farmed well) 1-2 Bracers, maybe Parts of Mekansm or Vladimir's Offering.
Your role/ What to do:
Use Dagger to get in, then use BKB to make yourself immune to their stuns/ disables, then use your Ultimate, Freezing Field. Use Crystal Nova and Frostbite to stop heroes that survived.
This is only an alt-tab guide, use it if you forgot something and want to look it up fast.