Predecessor Builds > Steel > Look out he's got a STEEL POLE!

Flux, Fist, Ela, are what I would consider 'Core'. Other three items are built to taste and what you need in game. Got a Grux/Kai/Crunch problems go tainted guard. Gideon/Grim/Morgi problems go chrysalis bastion. Look to see who's ahead, what their team comp is and itemize your defensive items around them.

Also remember don't run into the enemy team alone. Play around others, 1v1 if your feeling strong use abilities to isolate enemies and kill with team.

Early game do quick trades, RMB left click back, Q them through wave hide in your minions. Fist gives good sustain alongside passive which is when you want to commit to longer trades.