You get them from tournaments or as rewards. To use go to your inventory and then look on the instants tab. Click on it and then follow instructions.
Or go to your training and click the green icon and select the booster you want to use.
Sorry if these have been asked/answered already but I have looked and couldn't find anything
Is it better to fight or negotiate in the spire? Ie which works out cheaper.
Is there a pattern to negotiating - do certain types of spirit always want the same goods?
Must admit as a newcomer (6 months) I like tournament changes and can now get much further without severe losses.
FA chests have gotten worse though and third chest rewards are rubbish if you already have all the tokens.