Maximum CDR teamfight engages with [R].
Durability and crowd control
Guard allies you cast spells on and those that are very nearby. If you or a guarded ally would take damage, you're both hasted and granted a shield.
Whenever you gain a shield, your next basic attack against a champion deals bonus adaptive damage.
After 10 minutes gain 8 Armor and 8 Magic Resist and increase your total Armor and Magic Resist by 5%.
Gain permanent health when enemy minions or monsters die near you.
Creative tools and rule bending
You get free boots at 10 min. but you cannot buy boots before then. These boots give additional MS. For each takedown you acquire the boots 30s sooner.
Get a free biscuit every 3 minutes, until 12 minutes. Biscuits heal and permanently increase your max mana.
Guardian is a fantastic keystone for lane trading and teamfights where you need some extra defensive power for your AD Carry.
Shield Bash synergizes perfectly with Ornn's [W] granting you even more offensive trading power in lane.
As a top laner you'll be building a lot of Armor and Magic Resist allowing granting Conditioning a lot of value in bonus resists.
Overgrowth's health scaling makes you a strong front-line tank when paired with health stacking items such as Knight's Vow and Targon's support item.
Magical Footwear's raw gold efficiency is huge for supports as it lets you get to your crucial 2 item spike to offer massive teamfight utility.
Biscuit Delivery offers strong lane sustain to get through those pesky early poke lanes safely.