Right, so that SL/DE matchup. It's one of my least favourite matchups as DE, because it's so darn slow and grindy. SL can't attack because SL has problems attacking everybody. DE can't attack because combos. And shadows and monks are nigh unkillable. So what generally happens is that you and your opponent kinda line up opposite each other and a stalemate happens.
According to
Trip's excellent FAR (Faction Achievement Rating) analysis, at high levels, SL outperforms DE by 30%. 30%! That's huge! I think that DE does do rather poorly against SL, but I don't think that it's a 6.5-3.5 matchup in favor of SL.
Anyway, on to the guide.