TC, I just finished that boss fight as well, today too >_>
I wrote myself a little mini guide on notepad to get through it, so I might be able to help.
For Archeops, it has a choice *something* item equipped. So, it can only use the same move over and over again. Use that to your advantage. For example, I have a Vanilluxe, Scrafty, and Azumarill on my team. I threw my Vanilluxe, weak to rock slide, out against Archeops, so it would bait out the rock slide, locking Archeops into rock slide. Then, I would switch my pokemon to Scrafty, very resistant to rock slide. I'd use dragon dance to set Scrafty up, then kill Archeops, then dealt with the rest of the team, up until TalonFlame.
The Archeops moveset I saw it had was: Rock Slide, Acrobatics, and U-Turn. I don't know what it's fourth move was, it never used it against me.
As for the Mega Altaria, that thing one shot my entire team, aside from Typhlosion, and just barely. I ended up just cheesing it, using my drifbloon w/ Destiny Bond + quick claw.
Hope this helps! If another of Ciel's pokemon causes you trouble, I can help with that