Maokai

Strengths

Saplings can be tossed into brush for empowered effect - but don't stack well.
Try looking for flanks or other situations where Nature's Grasp is unavoidable or takes enemies by surprise.
Maokai's passive makes him extremely durable against focus fire from spells - so long as he can still basic attack something.

Passive · Sap Magic — Maokai's basic attack also heals him and deals additional damage on a moderate cooldown. Each time Maokai casts a spell or is struck by an enemy's spell, this cooldown is reduced.
Q · Bramble Smash — Maokai knocks back nearby enemies with a shockwave, dealing magic damage and slowing them.
W · Twisted Advance — Maokai contorts into a mass of moving roots, becoming untargetable and dashing to the target. Upon arrival, he roots the target.
E · Sapling Toss — Maokai flings a sapling to the target area to stand guard. More effective in brush.
Ultimate · Nature's Grasp — Maokai summons a colossal wall of brambles and thorns that slowly advances forwards, damaging and rooting any enemies in the path.

A suggested 5-lane lineup built around Maokai, based on hero partnerships and role synergy — not win rate.