Do you mean CURRENT MT or the next MT, whenever that is? If latter, don't ask now, ask then. You never know what you'll pull between now and then...
If current MT, Svarog or Vahagn (was she in current ticket...? No...? Then it's an easy pick I guess!).
Or, since you have Rudra, Vohu would be fine too.Mammon has been phased out of the very bestestest of Thunder teams, since she has no means of gaining +burst for herself. Don't get me wrong, Mammon is still GOOD, she's just not the BESTEST.
Kirin + SSR Baal is strong already (if you can tolerate that 90 second debuff), but Tyr and Marduk on top of that is quite the team already. The only problem you'd be facing is that both Tyr and Marduk are mediocre until Awakening, which will require 3 Dragon Eyes each. That's going to take a long, long, LONG time for a new player. Oh, and side note, bonus points for Marduk weapon being ridiculously good.
The next two Miracle Tickets would probably be Dian (healer extraordinaire) and Thunder Aphro. And then you'd be quite the beast. We are talking investing 30+50+50+50 bucks into the game though, so up to you.