Lehane might be the best Splash 2* though SoA or SoB kinda hurts her. Now if you look at mono decks, I think Sasha might take the cake.
Sasha: 7/2 Support +4 atk, protection Ability. That is +16 attack that can't be SoA'd or SoB'd! and she has only 1 pwr less than Lehane against full stops.
Lehane. This card will kick your ass hard. SOB for a 2** plus 2D and 8P is ludicrous. Add in her bonus, and you're looking at a awesome Bluff.
Sasha: I own her, and I can tell you most people assume she's a bluff, and waste their only good card in their hand, thinking they're gonna capitalize, and I put 2 pillz and they lose. +16 attack with Protection is totally worth it, add 7P and 2D, and Sasha is right up there with Lehane.
Spiaghi: -3 min 1 DR with 7 power and Montana bonus. Am I seeing this right? Spiaghi is known as another splasher, except when hit by SOA he really sucks. Add a pill with bonus intact and you opponent will half to pillz to beat, only to have a DR. Only bad part is Spiaghi has only 1D, and most opponents don't really care about that so they use their throwaway card on him.
Malysa Cr: 7P 2D with SOB and +2D. Almost as good as Lehane, but the reason Spiaghi and Sasha get the one up on her is neither are really affected by anything. Malysa Cr doesn't have pill-to-beat, only SOB, with is helpful but what about cards like Copper? What'll you do then? Not saying she isn't good, just lacking.
Arkn: I used to have Arkn. Let me tell you, Arkn is 1 very good tie-breaker card. He has 4D and kinda poor 5P, but his ability makes up for it. I'm sorry, but I'll take Arkn over Z3r0 D34d any day.
That's my list.