Anivia

Anivia works as a system, not as a string of buttons. Glacial Storm holds an area and keeps enemies chilled, which flips Frostbite into its empowered version on every cast. Flash Frost adds the stun when the orb detonates, and Crystallize turns open ground into a corridor of your choosing.

The price is steep. Before her ultimate she is one of the weakest mages on the roster: slow, mana starved, and defenceless once Flash Frost is down. Rebirth doesn't excuse bad positioning, it buys your team a few seconds to react. Pick her if you enjoy shaping space, not if you want to win by pressing buttons quickly.

Her terrain control has no equal here. One good wall cancels a dive, splits a team down the middle, or traps a runner inside a jungle camp. Her storm clears waves effortlessly once it's down and makes any contested objective unbearable for the enemy. And her passive forces them to kill you twice, which quietly ruins every dive they had planned.

The flaws are just as visible. She moves slowly, she owns no escape button, and Flash Frost travels slowly enough that anything with a mobility spell simply steps aside. Her early mana consumption is absurd. And a missed wall costs more than the cast: more often than not it hands an exit to the exact target you were trying to trap.

The first levels are something you endure. Take the chip damage, farm with autos, and don't throw Flash Frost for poke: it's your only stun, therefore your only answer to a jungler walking through the river. Hold it, and hold your mana, because an empty Anivia does nothing at all.

The ultimate changes the lane's nature. Drop Glacial Storm on the wave to shove without exposing yourself, and use it to apply the chill before every Frostbite. That sequence, not the spear, is where your damage lives. Aim Crystallize at the river entrances rather than at your laner: you'll convert more ganks into free escapes than you'll ever convert poke into kills.

The ultimate level is a hard break. Before it you survive; after it you own the wave, you shove when you want, and Frostbite is empowered on demand. That's the first moment where killing your laner becomes a plan rather than a fantasy.

The second spike is mana and cooldown reduction. Anivia is capped by her pool long before she's capped by her power: the first item that gives her both unlocks her whole style, because she can finally leave the storm running. The big power item comes after, and from there the full sequence executes anything that hasn't bought magic resist.

Stay on the edge, never in the middle. Your first button in a fight is almost never a damage spell: it's the wall, across the enemy initiator's approach line or behind their carry to cut the retreat. A wall that isolates one target is worth more than all the damage you'll deal that game.

Then place the storm on the choke they have to cross, not on the bodies: anyone walking through it is chilled, and therefore in range of your empowered Frostbite. And remember what the passive becomes in a brawl. Dying in front turns your egg into a gift; dying just behind your front line forces them to stand exposed to finish it.