Why the mangos and armor items ?
-Don't sell you mangos or use them unless you know you'll get a kill they are your cheap hp regen for most of the game till ! You get treads plus battle fury and solar crest.
-remember 2 mangos is cheaper then a ring of regen you'll have enough regen to sustain the laneing phase and jungle with a battle fury just don't use them unless its absolutely necessary !
-Firestorm is a great way to get cs and zone the other carry in offlane but use it to much and you won't be able to sustain you lane mana wise so pick up a sages mask and have fun!
-Solar Crest is a great item on Underlord because to forces all of the other teams right click carries to pick up mkb and raises his effective hp While combined with battlefury and hit talent gives him all the mana regen he needs to never go back to base! Allowing for nonstop farming and use of firestorm.
-Ac is ac you know why its good! more effective hp and attack speed underlord gets dmg on his own now he can abuse it!
-Finally skadi stats make him super tanky and slow what you hit most heros can't deal with that unless they can permastun
Pros / Cons
-Underlord is one of the best support hero's that can be played as a position 1 carry if needed.
-great with aggressive teams
-can disable multiple hero at once reliably
-super tanky at all points of the game
-reduces enemy teams physical dmg giving you the advantage against all melee heros
-high starting hp
-fast move-speed w/o boots
-can destroy squishy hero's in 1v1 silencer/lion/riki any hero with 700 or less hp
-turn around almost any team fight and take buildings extremely fast
-Lacks mana regen for his 3 high mana spells
-Lacks attack speed for being able to get the most out of his passives damage
-can be punished by sliences and magic based nukers dp/lina/luna/riki/skywrath mage
-his ultimate can be hard to time and master
-needs hp regen items to sustain himself at all points of the game