I know this is a question that covers a whole empire and there is more than one answer to it, but let me explain my situation. I just can't manage to keep up building my lines with all that control, defense and strong creatures around.
I don't find Voldore to be much of a problem since I can kill him with a fire arrow or a soul skill, but dealing with Soul Hunters + all sorcerers + sylph/undine destroy seems to hard for me as Gowen. I don't have any Blitz Soldiers, Panther Souls or uncommon soul skills so I usually go with Kurina+Monks, a strategy that dies rather quickly when the Sea Hunter hits the field. I tried outnumbering my enemy from early on, but last time I did that I got all my level 2 cards returned by a Grimoire card whose name I can't remember, and I ended up with a single Dual-Sword Weilder to stand against an army of 60 hp/30 atk/3 agi tanks.
Of course, it's a whole different story when they play the witch and keep me from using the monks or Kurina. My most used lvl 3 cards are the Revolver Knight and the Dual-Sword Weilder with Dryad buffs, all of which take a while to pull out and can't stand on their own against Falkow's lvl3s.
Anyway that's my situation. I know it'd be a lot easier with Spores or Blitz Soldiers but I don't have any of those and I don't plan to spend money. Any strategies or suggestions would be appreciated.