GK is a horribad matchup for Dragunities. Field spells killing each other field spells work both ways, except Necro is a much bigger problem card for Dragunities than the other way around.
What's a Kristya?
Also, got the new starter deck yesterday... Xyz monsters are... disappointing. They're good for two whole Xyz materials (At least the ones in the starter deck are) before they're crap... kinda wish Grenosaurus had better ATK. At least they have nice black starry backgrounds and are kinda cool to look at.
In terms of value for a player's standpoint, id say Kristya is the most valuable single right now at ~110. However, a pair of Warnings costs roughly 180 and virtually every deck needs a pair right now.