nealsfm
Member

Seven's ult can go through stairs

Warden's ult can also go through stairs

Wraith's ult can also go through the stairs if an enemy runs away behind the stairs before the ult turns the corner
View attachment wraithult_clip.mp4
Testing some other LOS abilities:
Abram's Siphon can go through walls, though this may be intended.
Haze's ult can go through stairs.
Bebop's Sticky Bomb and ult work through stairs, but his Hook does not.
Lash's Grapple and Flog works through stairs, but his ult does not.
Paradox's ult can go through stairs.
Pocket's Barrage can go through stairs and the bridge it connects to, though this is likely damage from the AOE as the visual effects stop on geometry.