I'm having issues beating Master level dungeons and was wondering if it is just b/c I'm bad or my team or what. My main team consists of a 71 WD Holy Isis, 76 E.S. Echidna, Maxed Green Odin (waiting to evolve when I have more team cost), 59 Verche KS, and 34 Chaos Dragon Knight. Currently rank 94. Any suggestions?
		
		
	 
It's any number of things:
1)  Your levels aren't high enough (CDK either needs to go or be leveled, get your Odin evolved, make sure you work to max skill that Echidna)
2)  By using a combo lead, you NEED to pair with another combo lead and make sure you can activate that leader skill every turn.  Pairing with a Horus isn't a terrible idea, but another Isis is fine for 9x team.
3)  In line with levels being too low, when you run a dungeon, make sure you can take the hardest hit OR be confident that your team can absolutely sweep the hardest hitters.  Neptune on Ocean of Heaven is a good example.
E4)  Like Ducarmel said...Some Master dungeons are harder than some Descended dungeons.  Keep that in mind.
You have a pretty strong team, but if you intend to keep CDK there, level him more.  Your best bet is to research Hera teams and build you a team to get your first Hera.  The game can be said for Two Heroes.  Hera is "my first gravity" and is basically a required sub for most teams (or Hades/Hera-Is).  Getting 2-3 Awoken Hera can really help.  
Two Heroes is a crazy important dungeon, too.  You want one of each of those guys.  Their busty forms are pretty much essential team members.  Max skilled, they can REALLY turn a fight around.  
If you're triggering Isis every single round, it's more than likely the fact that you need to work on a stronger team comp.  Remember that there is no single team that can tackle everything.  Even a Ra/Horus/Kirin team needs to be adjusted slightly to make up for various color deficient dungeons and such.  So that being said, build a few other options to play with.  As silly as this sounds, weakness/resistance is SUPER important.  Strong water monsters in a green dungeon is almost asking for failure.