iOS latest versions. My first valhawk battle. Not sure if this weird UI with unclickable buttons and overlapping text and weird traits is because the valhawk replaced their hero but hope this helps with a diagnostic.
Entered blood frenzy, no talismans or monoliths. This is PVP Aidana. I chose tier 3 fight. Invite = Tyler_gyfa Note: Update at end.
Update: Update: I did 2 more Tier 3 battles in Aidana blood frenzy and 5 Tier 3 in central spire, of which 1 central battle was a Valhawk all with no issue.