Warlock + Mother Cyst

[deathbymanga]

So, the requirements for Mother Cyst just say Cast Level 1st. and Warlock levels count as caster lvls, and the feat says the spells are cast as normally as you cast any other spell, so I have to ask, could a Warlock with the feat cast the Cyst spells as Invocations?

[Troacctid]

No, you cast the spells as you would normally cast any other spell. Since you do not normally cast any spells, you cannot cast the spells from Mother Cyst, either.

[praxidicae]

No, you cast the spells as you would normally cast any other spell. Since you do not normally cast any spells, you cannot cast the spells from Mother Cyst, either.

Nosomatic Chirugeon's Pestilential Touch might get round that as it allows the conversion of any spell-like ability into an inflict spell of the same level, and specifies in the text that you are "casting" the inflict spell.
I've done a bit of looking into this trying to build a spell-list onto the Warlock chassis and most feats that add spells/allow conversion of spells either specify that they are added to your class list (which the Warlock doesn't have), to your spells known (which again the Warlock doesn't have) or indicates that a spell-slot/prepared spell must be sacrificed in the conversion. In this case however the feat merely states "You cast these spells like any other spell you can cast".
The Nosomatic Chirurgeon can cast inflict spells by sacrificing a Spell-like ability of the same level. thus with Mother cyst they should be able to cast these spells in this manner.
It isn't really a particularly optimal use of your levels or feats, but could be rather appropriate and fun for a demented medic/plague doctor character.

[DarkSoul]

Nosomatic Chirugeon only allows you to cast inflict spells in this manner. It doesn't otherwise allow you to cast spells as a warlock, so you still can't cast the feat-granted spells.