I swear I need to just store this in a pastebin or something so people can link to it whenever Eliza talk comes up.
A.B.A. (Guilty Gear series): Easy, ABA has an alternate mode that she can switch to for a limited period that buffs her, gets a refill at the start of the next round. Can combo into this mode switch.
T.O.P. System (Garou): When character health is lowered to a certain amount, gets access to certain moves and buffs. This ties into Eliza's description as 'The Ultimate Attack-From-Disadvantage Character', losing blood along with health would give her access to specials only available with lowered health. Dunno how this would tie into the game with recoverable health already a thing in the game.
Donovan (Darkstalkers series): Donovan has certain moves that make use of his large sword, as well as being able to plant it into the ground.
Nanase (Street Fighter EX3): uses a staff weapon, has a moveset with and without the staff.
Anakaris (Darkstalker series): Egyptian/Mummy visual motif, as well as being able to detach his limbs for long range attacks.
Litchi (Blazblue series): Same deal as Nanase, has a moveset for when she's wielding a staff, one for when she isn't.
Jafar (Aladdin SNES): boss fights throughout the game have Jafar throwing his staff into the ground to summon magical attacks. No clue how this translates to fightan.
Jedah (Darkstalker series): Same deal as Anakaris, able to detach limbs for long range attacks. Makes use of various attacks using blood, including unblockable grabs. Wields a scythe.
Carmine (UNiB): Same as Jedah, uses blood attacks and has a scythe for a weapon.
Obviously all of this is pure speculation based on a list of gameplay inspirations that's months old and could have been revised internally multiple times for all I know. I know Mike's said a few times that he was looking forward to working on Eliza the least out of all the DLC characters.
EDIT: Also remembered that Mike has mentioned more recently that Eliza would have some function that works similar to Soul Body from Megaman X4.
Hopefully this helps answer at least some questions people are having about Eliza. Reminder that work on her has just barely begun, but with no delays like Squigly or Big Band hopefully more info about her will come out faster.