Presumably, like most Magikarp, it has some capacity to breathe outside of water, although I'm uncertain if it has any risk of air-drowning.
That said, The Authority loses before anyone could drown. I've heard, but if even a gentle breeze can blow him apart, than energy of Earth's gravity should.
Incidentally, is he in his Crystal Prison? Could the weakest Magikarp get past that?
Also, this is probably something for a revision, but:
Around 2000 B.C., the Authority chose Metatron to be his Regent. The Authority believed that conscious beings were becoming too independent, and together with Metatron, he planned to set up an inquisition in every world.
Metatron became more powerful than the Authority and seized control.
To keep dominance, he betrayed and trapped the Authority in the crystal box; this successfully kept the other angel alive, but imprisoned.
During the battle for the Republic of Heaven,
William Parry freed
the Authority from his crystal prison with
Æsah├ªttr . He died after being harassed by
cliff-ghasts .
"The subtle knife, also known as Æsah├ªttr or teleutaia makhaira was a knife with a blade so fine it could rip through the fabric between the worlds of the multiverse."
"William "Will" Parry (b. 1985) was the temporary bearer of Æsah├ªttr." Age: 13
I'm not entirely sure, but the Wiki's phrasing does suggest he survived briefly outside the Crystal Prison -although that defies calculations, IIRC & AFAIK, & the wind could just have started up later- if briefly.
It'd be also interesting to know the durability of it. Not to mention that assuming he was put in it around the year 2000 B.C., & not get killed until it was broken by a 13 year old boy around 1998, then The Authority was able to live nearly 4,000 years with that cage.
So.... With the cage there's a possibility he wins by longivity until Magikarp air-drowns or dies of starvation, dehydration, old age, etc. Or it gets broken by Magikarp, possibly, depending on what the durability of it is.
Without it The Authority likely dies to gravity.
