Laning phaseBuy what you need for the match.

Early greensBuy one of the first two. Buy Rebutal when needed.

MidGameBuy the first 3 to hit spikes ASAP. Cooldown is good for cycling abilities.

Situational CountersBuy each one according to enemy team's lineup.

SItuational LaningBuy if needed. Second row have the shielding items. Just buy those for burst.

LateGameThe three I think are must haves come late.

Survival ToolsI think Paradox's best way of not dying is to avoid damage. Run at least one

Ultra LateParadox's has the most impact early to mid, once it hits late your a utility and ult bot.

Bomb PivotItems here if you want to go bomb. Though this build is not based around bomb, so maybe look elsewhere.