Evil Genius

It's a Scale infection and secondary scarring because of the Scale. Treating the scale with a pesticide should give the plant some time to recover.

Well yeah, Trichocereus peruvianus, most likely Matucana. Reminds me of Rosei 1 or Sharxx blue.

First one is a Notocactus/Parodia. Something like N.warasii or N.leninghausii. The other plant is probably a Trichocereus spachianus.

These have great potential. More sun and they will look great. Seen some Trichocereus peruvianus, some Trichocereus bridgesii, one might be PC but hard to tell etc.

No worries, we've all been there. A good year or sometimes even two are needed to see smythe differences between certain forms and intermediates. Personally, I'm leaning strongly towards Peruvianus here.

Too small to give a precise ID, but very likely a Trichocereus peruvianus.

First one is a Cleistocactus species, but too young to tell which one. Second one is an Echinocereus, probably Echinocereus triglochidatus. Post it when it flowers and I'll verify it.

Hey mate, great to have you back.

Photos aren't great, but pretty sure the original damage came from splitting up due to watering more than the plant could take in. Fresh air and it should heal fine. If it doesn't post it again.

Second plant has scale too. Same treatment, Neem, Azamax, Spinosad etc.

The original plant suffers from scale, which then again causes substantial scarring. Look into pesticides against Scale, e.g. Azamax or something similar.

Hey mate, not sure what flower it is but it definitely isn't a Trichocereus flower. The whole flower development cycle on Trichocereus is totally different to that of the plants who have these flowers. It might be an aborted flower bud from a very early stage, but with how this looks it is honestly highly unlikely. It seems to sit on the areoles, but not in a natural way that flowers emerge from Trichocereus areoles. I am really sceptical of this, and I think it might've got stuck there by accident. But yeah, if this plant should flower at one point you know for sure. Do you have other pics of this clone? There are some cacti that flower like this, but they are other genera and this looks like Trichocereus bridgesii or something similar.

These are PC by the way.

Hey mate, there's all kinds of Trichocereus around and not all are PC. If in doubt just post them here and we're happy to help with the identification. Close up photos are important though. Blurry group pics are usually not good enough. Ps: no discussion about alkaloids please.

First one is probably Neoraimondia herzogiana and the second one is Echinocactus grusonii. Definitely no Trichocereus, but nice plants. The Neoraimondia are just beautiful in Peru.