provide a build and gameplan for me or a video that I can follow. I would like to try this in regular games
I usually go:
Soul Ring, Orb of Venom, Treads/Armlet (in the order you prefer), Heavens Halberd (the evasion is glorious and shuts down a carry), Mjollnir/SkullBasher, Assault Cuirass.
Points on Purification first, then analyze the lane, does it have magic damage? Then put points on Repel (one might suffice though), otherwise, focus on Purification/Degen Aura.
Farm up and stay in a lane with a support that has a stun. You usually jump first and start hammering them, the support stuns, and you finish with the Purification and in Early game this is devastating. If the support is not there, just play safe and spam Purifications on your creeps to farm with Soul Ring (If you are offlane and badly outlaned)
When everyone starts fighting together, just Repel yourself or the strongest carry, and go whack shit at them. Usually it starts with everyone ignoring you because "lol Omniknight" but then they see you are hiting fast due treads and Armlet of Morddigan and actually doing damage, then they panic, and then they die because you have healed yourself and killed everything in your proximity. When you feel it's safe midfight or out of mana to place a Purification, use Soul Ring.
Continue building your items, remember to always use the ultimate when you and the rest of the team are getting attacked. Never use it just to save yourself, otherwise it might go badly. Despite feeling invincible due the Heal, Invulnerability and Magic Resistance, remember that you aren't invincible, and play with your team.
This build also works very well:
http://www.dotabuff.com/matches/1069880623 but instead of a Butterfly I would go for the HH again.