Morphling is a ranged agility carry. With the ability to morph his strength into agility and vice versa he can quickly transitioning from being a hard-hitting right clicker into a tank who is also potentially elusive.
He truly shines in the late game where his ability to shift his strength into agility gives him a huge stat advantage.
Skills
Waveform is usually skilled and maxed first.
Adaptive Strike is always skilled and maxed last.
Morph Agility/Strength Gain is usually skilled and maxed second.
Replicate is always skilled (levels 6, 11 and 16).
Items
Starting Items: Tangos, Healing Salve, 4x Iron Branches (or 1x Slippers/Circlet).
Early Game: Power Treads, Magic Wand.
Core Options: Linken's Sphere (standard build), Manta Style (early fighting), Ethereal Blade (greedy aggressive).
Luxury Items: Black King Bar, Butterfly, Eye of Skadi, Monkey King Bar, Satanic, Daedalus.
Situational Items: Hand of Midas (early greed), Ring of Aquila (early, cost efficient), Drums of Endurance (early fighting, stats), Bottle (if mid), Boots of Travel (late game 6 slotted).