It's also worth mentioning that Niko works very nicely with enchantment synergies, like constellation

Aang and La, Ocean's Fury Aberrant Aberrant Manawurm Abomination, Irradiated Brute Abomination, Terrifying Titan Abomination, World Ravager Abyssal Persecutor Aetherstream Leopard Aetherwind Basker Agatha of the Vile Cauldron Agatha's Champion Agent Frank Horrigan Aggressive Mammoth Agonasaur Rex Ajani's Comrade Akawalli, the Seething Tower Akoum Stonewaker Akoum Warrior Akroma, Angel of Fury Akroma, Angel of Wrath Akroma, Vision of Ixidor Aku Djinn Akul the Unrepentant Alexios, Deimos of Kosmos Almighty Brushwagg Aloe Alchemist Alpha Deathclaw Altanak, the Thrice-Called Altar Golem Amarant Coral Ambush Krotiq Anax and Cymede Ancient Imperiosaur Ancient Stone Idol Ancient of the Equinox Anep, Vizier of Hazoret Angry Mob Angry Rabble Annoyed Altisaur Arahbo, Roar of the World Arbalest Engineers Arborback Stomper Arcbound Crusher Archdemon of Greed Archdemon of Unx Archetype of Aggression Archon of Valor's Reach Archweaver Arctic Nishoba Argothian Swine Argothian Wurm Armada Wurm Armory Paladin Arrogant Wurm Ashroot Animist Assaultron Dominator Atalan Jackal Atarka, World Render Atsushi, the Blazing Sky Attuned Hunter Augmenter Pugilist Aurelia, Exemplar of Justice Aurochs Aurochs Herd Aurora Awakener Autochthon Wurm Avatar Kyoshi Avatar of Growth Avatar of Might Avatar of the Resolute Avenging Hunter Axelrod Gunnarson

Ugin's Labyrinth banned in Brawl
It's a great one drop and tap for mana, second turn swing with your land to hit people with poison counters prior to setting up their defenses