In this sense, Horn of Valhalla both acts as a way to develop your board and as a payoff once your board is developed, which is quite powerful
Hitting him for less than his toughness multiple times won't work, as he'll just keep healing
To compare the two versions, NM copies of the normal card commanded a high north of $30, but the Reverse Holo more than doubles that, with its highest sale at over $68
I think Hisuian Zoroark VSTAR can have some chance in the format but looking at its requirement, it's a bit tricky
At ~1,000 less per box, S10D is the slightly more affordable Hisui paired set
We have attended international conventions, met collectors from all over the world and discussed amazing decks