For the most part, these function the same as sagas normally do, giving you chapter abilities for each turn that they remain in play, except they can also attack and block just like normal creatures
(2019-10-04) Kenrith's last ability can target a creature card in any player's graveyard
It's much cheaper, it gives you some board presence, and can even be used without another character on board (you can target Cogsworth himself with this ability, turning him into a 1/1 Rush)
The first four sets will rotate out of the Core Constructed format, but will still be available to play in a new format called Infinity Constructed
Avalanche of Sector 7) and that's being generous
A handful of cards help protect characters or heal their damage, including the Dinglehopper, which can continuously remove a point of damage every turn