I'm not sold on the idea, though I like the sound of Empathic Removal.
First question I have is are you running a type of Monk defense? The build seems tailored that way I suppose, because your damage output isn't where it should be, I think. I like Leaping Mantis Sting, but given the general "meh" feeling I get from Fox Fangs, I wonder if the Lead and Off-Hand can get a bit of an overhaul?
Two, if you're running a more offensive (or at least, a sort of mid-field character, if such a role exists, lol) character, wouldn't Unsuspecting Strike-->Black Lotus Strike-->Critical Strike be more effective?
Three, given the "Other Ally" clause of Gift of Health, I couldn't imagine this character is terribly offensive, so I suppose that's why I'm a bit on the fence about this guy. Should an Assassin really try to heal allies? That's the quasi-philosophical question here, isn't it? Should an Assassin ever try to heal allies, even as an emergency heal?
Gift of Health would certainly be worth bringing as a self-heal, if it could heal yourself, but as it stands now...I don't think it's really worth it for a build of this nature.
The very idea behind Gift of Health seems flawed, actually. Maybe that's why I'm not sold on this build...the only characters who could use it are either Monks or spellcasters with Monk secondaries. Heal Monks wouldn't use it because of the disable effect. Maybe Boon Prots might. N/Mo doing Monk support, absolutely. Rezmers with some WarHate from Illusion, absolutely. But I'm not seeing combat classes doing it.
I think it would need a change in order to be viable...change it from Target Other Ally to just Target Ally, and have its effectiveness both directly proportional to Healing Prayers and inversely proportional to Divine Favor. The higher the Healing Prayers, the more effective Gift of Healing is, but the higher the Divine Favor, the less effective Gift of Healing is. Perhaps even raise it to 10E.
But that's neither here nor there, because we won't see those changes, and either way, the build will still be an Assassin doing so-so damage and trying to double as some sort of emergency back-up Monk. And I can't quite see that as viable.
Going back to Black Lotus Strike, it would need a hex, so if we--though this is changing the entire idea behind your build I suppose, though I'm keeping Empathic Removal, so who knows--slide some points out of Healing Prayers (perhaps drop Healing Prayers all-together?) and into either Deadly Arts or Shadow Arts, and replace Gift of Health with either Siphon Speed (Deadly Arts) or Way of the Lotus (Shadow)...how would that work for you?
Siphon Speed would work as your snare and speed boost, and Dash is there in case Siphon Speed is removed. That seems viable.
If you went Way of the Lotus, your energy return is going to be nuts. From Black Lotus Strike+hex, you're getting 5-17E back. Then from Critical Strike+WotL, you're netting...5-13E+3E from Critical Strikes/Critical Eye:
Critical Strikes: 10+3
Dagger Mastery: 10+1+1
Shadow or Deadly Arts: 11
Empathic Removal, 5e 1 10s elite*
You and target other ally lose 1 Condition and 1 Hex.
***slot for either Siphon Speed or Way of the Lotus***
Unsuspecting Strike, 10E - 4s
Lead Attack. If this attack hits, you strike for +1...25 damage. If your target was above 90% Health you deal an additional 10...34 damage.
Black Lotus Strike, 10E - 30s
Off-Hand Attack. Must strike a Hexed foe. If it hits, Black Lotus Strike strikes for +1..25 damage and you gain 5...17 energy.
Critical Strike, 10e - 6s
Dual Attack. Must follow an Off-Hand Attack. If it hits, this attack strikes for +27 damage and results in a critical hit.
Critical Eye, 5e 1 30s
Skill. For 32 seconds you have an additional 6% chance to land a critical hit when attacking. You gain 1 Energy whenever you score a critical hit.
Dash, 5e - 15s
For 3 seconds you move 50% faster.
Res Sig
Now, the only thing I'm not really liking about that is the recharges. WotL has a recharge of 20 seconds. Black Lotus Strike has a recharge of 30 seconds. What may be a good off-hand for this is Golden Phoenix Strike.
Golden Phoenix Strike, 5E - 8s
Off-Hand Attack. If you have no enchantments on you, this skill fails. If it hits, Golden Phoenix Strike deals +10...26 damage.
I would think it's possible to have some sort of enchantment on you, even if it's Shadow Refuge (in place of the hex, since Black Lotus Strike isn't in the bar anymore).
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Yeah, I don't know if I helped at all, because my post sounds really wishy-washy, but maybe I gave you something to work with? lol