>>21966613For theory sake, let's discount that 151.
151-153: Amphoros line
154-156: Raichu line (new Mega for Pika and Rai, speed based for Pika, offense based for Rai)
157-159: Luxray line (now Electric/Dark)
161-163: Magnezone line
164: Rotom
165: Heatran
166-167: Volcorana line
168-170: Delphox line
171-173: Mamoswine line
174-175: Weavile line
176-178: Snorunt line (w/ new Mega for Froslass)
179-181: Aegislash line
182-184: Gigilith line
185-186: Crustle line
187-188: Exadrill line
189-200: Golurk line
201-202: Diggersby
203-205: Dusclops line (new Mega)
206-208: Dragonite line
209-211: Haxorus line
212-214: Hydriegon line
215-223: Eevee+lutions
224-226: Clefable line
227: Mawile
228-229: Zorark line
230-231: Lati@s
232-234: Genies
235-236: Tyrantrum line
237-238: Kabutops line
239-240: Cradily line
241: Aerodactyl
242: Suicune
243: Entei
244: Riakou
245: Lugia
246: Ho-oh
247: Groudon
248: Kyogre
249: Yvetel
250: Xerneas
251: Rayquaza
252: Mew&253: Mewtwo 