Considering that that the green member of the M20 cavalier cycle - Cavalier of Thorns - is currently pushing $20, there is probably still room for Cavalier of Flame (planeswalker stamp) to grow, although right now the green Cavalier shows up in 14% of Pioneer decks while the red one is in less than 4%, which means it's going to take a lot more play for Cavalier of Flame (planeswalker stamp) to get anywhere near Cavalier of Thorns price
Technically, this will be a slow death over time, halving an opponents life total with each hit
Johnnies dont get many these days, so grab what you can
This looks like a great sideboard card and nothing more
You may activate it with no targets just to put a loyalty counter on Tezzeret
This mechanic has any player with Rad counters on them mill that many cards from their deck, losing one life for each nonland card milled this way, and then they lose one rad counter