Magic damage and reducible crowd control are the main threats
Mercury's TreadsChange the boot choice for the damage and control you are actually facing, rather than following the default armor purchase.
Amumu
the Sad Mummy
About Amumu
Legend claims that Amumu is a lonely and melancholy soul from ancient Shurima, roaming the world in search of a friend. Doomed by an ancient curse to remain alone forever, his touch is death, his affection ruin. Those who claim to have seen him describe...
BUILD
Guide sources Durable engage
Core items
1
2
3
Why this setup?
Stay alive through first contact so your team can use the space and crowd control you create. This is a defensive teamfight baseline, not a claim about the highest-win-rate setup.
Item choices
Sunfire AegisHealth and armor support close contact; the damage aura contributes while you remain beside the frontline and monsters.
Abyssal MaskMagic resistance helps against spell damage, while the nearby magic-damage amplification can serve allies following your engage.
Jak'Sho, The ProteanMixed defenses are a later option when fights last long enough to benefit from staying engaged.
Runes
Select a rune to read its effect.
AftershockKeystone
After immobilizing an enemy champion, increase your Armor and Magic Resist by 45 + 75% of your Bonus Resists for 2.5s. Then explode, dealing magic damage to nearby enemies. Damage: 25 - 120 (+8% of your bonus health) Cooldown: 20s Resistance bonus from Aftershock capped at: 80-150 (based on level)
Font of LifeResolve
Impairing the movement of an enemy champion restores @BaseHeal@ Health to you and the lowest health nearby allied champion. 70% effect for Ranged Users. Cooldown: 20s
ConditioningResolve
After 12 min gain +8 Armor and +8 Magic Resist and increase your Armor and Magic Resist by 3%.
OvergrowthResolve
Absorb life essence from monsters or enemy minions that die near you, permanently gaining 3 maximum health for every 8. When you've absorbed 120 monsters or enemy minions, gain an additional 3.5% maximum health.
TriumphPrecision
Takedowns restore 5% of your missing health, 2.5% of your max health, and grant an additional 20 gold. 'The most dangerous game brings the greatest glory.' —Noxian Reckoner
Legend: HastePrecision
Gain 1.5 basic ability haste for every Legend stack ( max 10 stacks ). Earn progress toward Legend stacks for every champion takedown, epic monster takedown, large monster kill, and minion kill.
OffenseAbility Haste
+8 Ability Haste
FlexHealth Scaling
+10-180 Health (based on level)
DefenseHealth Scaling
+10-180 Health (based on level)
Situational items
Choose according to the enemy team.
Attackers with healing are the targets you must hold
ThornmailArmor and anti-healing can fit that job. Check that its trigger is relevant to how those enemies deal damage.
Your team already has a dependable frontline and needs sustained magic damage
Liandry's TormentThe health and ability burn can convert time in range into pressure, at the cost of a defensive slot.
Route
Finish a useful clear or reset rather than forcing a low-information fight just because Bandage Toss is available.
Engage
Check which ally can reach your target before spending the second control layer.
Peel
Keep control for the enemy entering your carry's space when protecting that carry is the stronger fight plan.
Build guide. Sources