Can a psyker with the Erasure power use it to remove his own recent memories?

Probably, though I would add the caveat that he remembers he actually erased something, since deleting the impulse for erasure during the erasing would terminate the process.

Gonna go with 'no':

The psyker chooses a single foe in range and line of sight who opposes this power with a Willpower test.

I'd quip in that if you're willing to mess around with your own brain using the powers of the warp, you're already your own worst enemy per definition.

On a more serious note, if you're looking for memory alteration that is reliable, and comparatively safe, your local inquisition should have access to mind cleansing techniques to remove sensitive knowledge.

I'd allow it with a modifier of -10 to the roll, because you try to temper with your own mind. BUT I won't allow it to delete corruption points gained through blasphemous knowledge gaint, because the corruption of the soul is not dependend of memories. Also I'd allow it to delete Insanity points gained through the deleted memories, but roll 1d10 (or more/less depending on the circumstances) Corruption points, because he just let the FRIGGIN WARP into his head and that HAS to leave some bad vibes behind.

I would allow it, but if they have talents making them more resistant against mental powers then make them suffer that difficulty as well. Their conditioning becoming their own worst enemy. Now as to why you'd want to do that I don't know.

I wouldn't let it delete IP, I'd give IP for it.

Thank you all for the ample feedback!

I wouldn't let it delete IP, I'd give IP for it.

Maybe you could take away the IP they got because of something they witnessed and instead get 1d10 IP (or some other appropriate amount), because, well they deleted some part of their brain.

No they want to forget something fine, but that doesn't mean psychosis goes away, it just modifies itself. There's a gap, you're going to fill it with something.

I can't believe someone is seriously suggesting letting psykers selectively edit their own minds to reduce their insanity points. Way to completely undermine one of the main themes of the game, guy.

IP could be bought off via XP in prior editions. I see no reason why this method shouldn't work to those costs(as the roots of insanity generallly are tied to experiences, which give experience points, such reductions costing XP makes even more sense). Never mind it's genuinely risky and failures as well as glitches should prove FUN as per the dwarf fortress definition....

I can't believe someone is seriously suggesting letting psykers selectively edit their own minds to reduce their insanity points. Way to completely undermine one of the main themes of the game, guy.

Well, my first idea was to allow it to trade IP for CP. After ThenDoctors interjection I modified my idea as to allow it to delete IP gained by the deleted memory (so most likely something between 1 and 5, maybe more) and roll 1d10 instead for new IP, so it will be a gambit on the players end. Maybe if they got a certain phobia from the encounter it could be traded for a new one with that (maybe a fear of the lost memories, so the character would actively try to avoid remembering?)

Also DBGs idea with using it as a way to explain buying of IP is great.

I think buying off IP was a dumb rule in it of itself.