A very pissy Pint just about to hit a freakout point into a chalkurite one limb at a time whilst he copes with brain liquifying from his eyes turning into radioactive mini wormholes in their sockets

Ylem (the black stuff) usually manifests first at extremities from the chalkurite’s fight/flight response, in pint’s case being the former. It’s a point of no return when they trigger full form capacities and usually this stage lasts for about five minutes—at which points people have hoped to clear of the area since the full shift triggers massive radiation waves and produces ylem (that around a very angry chalkurite responds by crystallizing into jagged and potentially dangerous forms—if not that, then its hungering state will swallow anything and anyone nearby)

Berserk full forms don’t last longer than 30 minutes at which point the nexus in their masks destabilizes and returns the chalkurite to their anchor self (human)

That is more than enough time to wreck an entire city to be honest or survive anything that triggered the chalkurite into such a state.