My previous longest streak was 7 wins with Orizone. Unfortunately, I ran into its hardest counter for the 8th match: Silvally-Rampardos.

I then messed around with Suicune and Mega Venusaur for a bit, but these 2 decks got countered easily (i.e. lost after 1-2 games).

Thankfully, the ever trusty Dark Greninja pulled through.

Here is the deck for reference; nothing new here: