Xenoblade - I got to the point where the Mechon attack the city. I'm now busting shit up with the Monado. But then I encountered this big face mask boss that requires a chain attack to "break" it. Well, for the life of me, I couldn't do one! Yes, I saw the ultra=brief tutorial on it, but I blanked during the battle. Something about matching colors or some other nonsense. I go to check in the manual, and there's no Chain Attack section! Ugh. Ended up just turning the game off because I couldn't hurt the guy, and couldn't flee the battle.
All you need to know is that Pink Arts inflict Break
and Green Arts are the ones that inflict Topple
. With a full party gauge (blue bar on the top left corner of the screen) press up on the D-Pad at any point on the arts' pallet (doesn't matter where) until the center circle is replaced by a blue circle with a white triangle symbol in the middle then press that. Then have Shulk hit the boss with one of his Pink
arts and it should switch to Reyn where you use his Green
art to topple the boss (then have Dunban do whatever; Monado Buster, Gale Strike, whatever).
Or to summarize: If you're playing as Shulk: Chain Attack, Pink, Green, Profit. If you're playing as Reyn: Wait for Shulk/Dunban to inflict Break, Chain Attack, Green, Profit.