For using Ragnagord, I'd highly recommend this configuration instead:
Why? Well, in the my ten test battles with your configuration, I got completely stalled by there being no brown matches available three separate times.
To get things started, you need:
1 brown match of any kind
or 3 purple/red surges, a match 4 and two surges, 4 matches and a surge, etc
or 2 blue surges (4 matches), then an acolyte cast to get your browns on the board and then a brown match if you don't get an extra turn (which you probably wont)
You will, occasionally, gather less than half mana for both exploders and be in a worse position than when you start, needing either a brown surge or two purple/red surges to continue.
The above configuration, you can start exploding with:
1 brown surge
1 red surge
2 purple surges
any combination of 2 brown/red match 4/5s
1 blue surge and 1 blue match fills warlock, who can remove purple but possibly kickstart getting browns on the board if you get stalled
Even on a low yield explode (lots of yellows/greens/blues on the board beforehand), you can usually focus down purple, red, or brown to continue exploding after one match, since they all have bonuses. The AI will generally try to starve you, but they can't take all the mana colors.
Target purple when exploding, unless you can get way more of the board otherwise. Both exploders should be much easier to fill given the available mana. Also, you'll get +1 magic from having three mystics and some life or something from having . It doesn't really matter much, but if you have a level 19 dragon soul and an even amount of magic kingdoms at 5 star/level 10, you'll get an extra explosion out of it. It's a pretty good variant to the giant spider/TDS/necro/necro build otherwise, having one less color able to charge with but also potentially starting one turn faster.
It is also pretty decent swapping out TDS for Banshee, which is the build I've been testing for those that don't have TDS, but I prefer having a green mana "closer" in this setup (like Rowanne) rather than double necro. Which brings me to:
This one uses one epic you currently have to pull randomly, and one from a kingdom quest, but I find it a lot more fun than than stuff like Valk triple warlock or Valk triple anything with necro configurations or the ones that rely on plinking the enemy down one hit at a time.
Rowanne (no traits)
I use Banner of Progress (yellow/red) for this configuration, which, along with the link traits, gives +1 red, yellow, brown, and purple. You can also use the Vampire banner (red/purple), which allows Banshee to fill in a purple match + a purple surge, where with Progress she will need a minimum of two surges or three matches starting from nothing, but you generally wont be filling banshee first. Ragnagord fills in one surge, Explode fills banshee or close to it, banshee fills ragnagord, Ragnagord refreshes the board to do it again. Banshee is unblocked and fills in any three matches. Two cycles, then clear with Rowanne. You don't really need extra turns on Banshee, you just need enough blue to red alignment to get your mana up. High end players that don't need souls can just use rowanne after the first explode and clear it.