Darv doesn't need the boost if he's using a normal attack making Dandelga the better option since Black Lance only functions on normal attacks. Between the other weapons, hit spheres, Ishir's, and Evil Shards/equivalents I'm not sure I'll ever equip the thing to be honest. It might get slotted on a B team v a trial where you actually want to be using more than one squad but if you have the other current end game spheres it just kind of falls flat. If I didn't already have Maxwell I would probably have used it on Zelnite but there's no content atm where it's worth a slot. Maybe for Cardes but I haven't bothered to look that fight up yet.i can't really think of a scenario where you would need to condense a Lilly and mitigator into a single unit. especially if you have a Darvanshel since he does damage and can almost constantly keep his BB going every turn. where with Narza you could very easily break the cycle of SBB every 3rd turn by having to use his BB for mitigation. that's just from my experience trying to use him to beat the Maxwell trial though, so it might be easier in future content to use Narza as a combination Lilly/mitigation unit. or maybe using ares excelsior LS with the right spheres could keep his BB gauge filled each turn. or maybe i've gotten spoiled with constant mitigation with Darvanshel
also having trouble deciding who would benefit best from Magress sphere... thinking Darvanshel since Black Lance fills 4-6BC when attacking, with Ihsir's guise leaving 4BC from using his BB his gauge should be almost half full before taking any BC drops