Even though the wording does not indicate they need to present, it appears that Aces & Eights, as a Team-Up, cannot be used if there are no Charged tiles present.
“Deals 23,327 damage plus 3,365 for each Charged tile on the board…”
If there are no Charged tiles on the board, it should still deal the base damage,
“Converts all Charged tiles to basic tiles, then creates 3 Charged tiles.”
If there are no Charged tiles, then there’s no Charged tiles, and so it should convert zero tiles to basic tiles, i.e., first component has no effect, but then it should still create 3 Charged tiles.
Neither effects of this power require the presence of Charged tiles, and so their absence should not be preventing the power from being used.