here are 3 Free Kingdoms characters that are, well, not buddies with Anton but I'm sure their paths will cross quite often ^^
One of the things I had to decide early on in developing the set was if characters designed to be summoned should even be in decks. After all summon characters are essentially tokens. Magic just made token cards that you kept beside you and put into play to replace a token. That is essentially what the summon mechanic is. When the set was fist being worked on, PI was still producing cards and I did not want to make cards that were only tokens, so I decided that all cards should be useful in a deck even if the primary function of their theme was being summoned. Which is why you will find a number of cards with "After entering play from your hand" card effects, like the previously seen elves and the Yscarite Pack below.
Free Kingdoms is actually not one of the factions that has a lot of summoning. They are in the middle, but one of the problems with summoning is that it primarily brings in low level characters and Free Kingdoms do very well putting out a lot of level 1's and 2's and buffing their attacks. So, while Free Kingdoms do have summoning, most of it is at a cost to the summoner and is not useable every turn.
And so we see Essek the Creator who wanders about giving the Gift of Yscar, and then disappearing to cause mischief elsewhere.
Threndil Yscar is primarily, and obviously, Anton the Everchangings helper. In case you missed it before, Anton can use the actions printed on any Lycanthrope in play, not just ones in his army.