1- Mismagius
2 - Spiritomb
3- Shedinja
4- Golett
5- Golurk
6- Gengar
7- Duskull
8- Sableye
9- Banette
10 -Gastly
11- Rotom
12- Haunter
13 - Banette (?)
14- Lampent
15- Chandelure
16 -Giratina ( the next is alt form or original form idr)
17 - Dusklops
18 - ??? (The pair of eyes in the roof, to Mismagius left, sorry i forgot to circle this one)
19 - Shuppet
20 - Dusknoir
21 - Jellicent
22 - Frillish
23 - Frosslass
I cannot find Misdreavus,Drifblim (although one could say the detail in the window,depicts Drifblim),Yamask,Cofagrigus; strangely the numbers doesn't add up.
Not counting number 18 - which I don't know who is - we have 22 out of 27, with 4 not identified.
I may have skipped or not seen somebody though.