Hei Lian

Displace first, then pay 1 IKZ: Hei Lian gets +1 Attack until the end of the turn, once per turn. A Leader has no attack of its own, so on a turn without a weapon this gives her 1 attack to swing with; with a weapon it adds 1 to the weapon’s attack.

Water’s displacers turn it on: Back Alley Abductor, Gabu (cost 2 or less, whenever it enters the Garden), Drowncalling Siren (base cost 3 or less), Sentinel of Passage, Usui (cost 1 or less, while their Alley is empty) and Tidal Wave (every entity costing 3 or less). It must be an entity in your opponent’s Garden, and you must be the one who displaced it.

She is the only Whirlpool Leader, so Submerging Tides, Inoe’s discard-2 displace works only under her. Rainworn Gate, the deck’s Gate, lowers an opposing entity’s cost so Gabu, Usui, Inoe and Tidal Wave reach bigger targets; the Siren checks base cost, so the cut doesn’t help it.

A displaced Defender can’t redirect your attacks, so the displace that turns on her ability also opens the path to their Leader.

More displace from the full set: Puddle Abduction (2 IKZ, cost 4 or less), Waterthread Bracelet, Lowtide Jack (on a portal), Elora the Voyaseer and Alley Mudcrab. She also takes 1 off Qingyue, which costs 1 less per Whirlpool leader or entity in your Garden.