That's a impressive line-up for 28 draws.That aside, in order to at least 3* map 7 you will need 4 healers(yes 4 HEALERS, unless you can roll out Marr before the event) and at least 3 duelist as well as a solid tank.It's a shame you don't have Imelia but a newbie won't be able to AW a unit in a few weeks anyway, so I suggest you work on Leeanne for now.Your 3 duelist should be Lyla, Conrad and Mortimer/Eunice(I don't include Sybilla in here because she is a black lvl will be much harder compare to silver and pla, but if you use her she should at least be in 60 - 70 to be decent, the video guide use a AWed Olivie but since Olivie has paper health you can just lvl Sybilla to 60 - 70 and take care of the healers firs)t.But tbh you'll need to spend more to get silvers to CC your pla otherwise it would be quite a long stretch and did you use your silver to CR already because that's way too few healer I see.Oh and another thing, you shouldn'y use Lyla as a lightning rod, just spend a few and try to get Niel, or better yet, Sophie instead, the ability to avoid melee is invaluable in this event.
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If you watched the video you could see that the lightning rod should not lose health outside of range attack(I mean they should not engage in melee).Angel is the most suited for this task, beside Sailor and Puppeter.The Lich King attack is way too painful even with 20 MR( which is Niel MR in DMM, only 10 in Nu).A duelist will engage in melee and lost even more health, strain the healer even more.