I've read somewhere psvita can screen mirror from ps4. How convenient that be?

Yes remote play is what they called. Meaning psv is directly connected to ps4 to play games? Or need some other device like repetitor or router? The connection won't require Internet Connection right?

Meaning still need another router. Maybe can use phone's mobile Hotspot as Local Connection? Is that possible?

Oh, I thought need somekind of router/Wifi to be in same network. So Psvita and Ps4 can connect directly.

Yes, I mean only within same house. Like first and second floor only. So there's various way to play ps4 using psvita. Superb.

Can be bought from lelong.my I guess