Characters may only teach one skill and one power per event.
Generally, a character can only teach a tree or skill once they have mastered it (i.e., all possible levels have been purchased). Shifters and Gifted Kinfolk may only teach innate gifts but do not need to fill a tree before they can teach it.
Characters can only have one taught power and one taught skill waiting to be purchased at any time. If you are taught a new power or skill before spending XP to purchase the first one, the teaching will be lost. The character doing the teaching must submit a teaching report to Check-in in order for the learning character to be able to purchase the power or skill.
Once a character has been taught the first level of a skill, they can progress without needing individual tutoring for each step. The exception is Shifters and Kinfolk, who can learn a gift out of order from its tree, but each learned power must be taught individually.
Some powers offer what may seem to be the same magic as others. If you already possess the powers granted by a certain level in a given power tree, you may take that power level for free, provided you meet all other prerequisites. Taking a power in this manner still counts toward your one-power-level limit when advancing at Check-In. Corrupted or dark arcanoi versions of powers do not allow you to take non-Corrupt versions for free, but non-Corrupt versions will allow you to take Corrupt or dark arcanoi versions for free.