Increase your Tenacity and Slow Resistance for each summoner spell on cooldown. Immediately after casting a Summoner Spell, gain a larger burst of Tenacity and Slow Resistance for a moderate duration.
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.
Grasp allows you to heal substantially mid-fight, and thanks to Mundo's auto-attacking nature from his [E] steroid, Grasp will also provide a decent amount of extra damage.
WhyDemolish
Mundo is great at taking towers as the auto reset and bonus AD from [E] allow you to quickly chop them to pieces.
WhyConditioning
Conditioning's extra resists are extra strong when combined with Mundo's high health stacking nature making you a massive front-line tank.
WhyUnflinching
Unflinching's extra bit of Slow Resist and Tenacity is perfect for allowing you to stick to your target and keep theming burning with [W] and point-blank [Q]s.
WhyMagical Footwear
Magical Footwear's mid-game item efficiency allows you to quickly get to your core tank items.
WhyCosmic Insight
Cosmic Insight's general utility always comes in handy, keeping your [Q] on a short CD for extra damage and slows.