Irelia wants neither a full burst build that abandons her once the fight extends, nor an overly tanky build that removes all threat from her entries.
Long Sword
Proc Sheen on each dash Q Bladesurge, burst constant
%HP on-hit amplified by Q resets in combo
survival in extended fights, heal on kill after resets Q
Gluttonous Greaves
Stasis
Each Q Bladesurge on minions or enemies stacks Conqueror toward the passive Ionian Fervor.
Extra shield mages in lane mid or the supports AP in teamfights.
Lane sustain recover between his rotations of Q Bladesurge.
Accumulated HP to she survives his dives after a R Vanguard's Edge.
Q (Bladesurge) dash triggers penetration on each jump on a target.