>>536472423
It's pretty universal that the only thing that can repel the Ultimate Browheel is an Ultimate Projectile, and the projectile has to hit the bros before it hits Lowain or else they'll roll right through and hit you anyway. A lot of projectile ultimates are single hit, so a couple characters stand out as having better counter to it, like Anila's triple sheep, Vira's Luminiera and Percival's carpet (when close enough to hit twice).

It can blow through any armored moves that don't have Unlimited Armor (like Soriz's punch and Vas's ) because it multi-hits on the way by.
It's one of the few projectiles that move fast enough for Yuel to backflip to avoid in the open. Of course she'll get hit by any followup from Lowain before she can land. Yuel has no real option but to block or DP.

Eustace's charged shots can stop the bros without spending resources, but it would need to be a super hard read or pure luck to have a charged shot ready before the attack reaches you. But you're only going to hit one or the other, so regardless of which one you hit, the other will hit you unless you're near fullscreen away. His only option is to spend meter.

Two definitive meterless counters I've seen while skimming so far are on Anre and Zooey
Anre's 236x of any strength can stop the bros, but this is a unique case where you want to hit Lowain first as it hits both of them. If you hit the bros first, Lowain will go unhit and be free to punish Anre.
Zooey's 66H can shield charge through the whole thing without issue and will fuck up Lowain if he pressed anything. The best option as long as you have six frames to act and Lowain didn't just block afterwards.