There are 5 cards set on Ikoria, so one of them must be a real clue. This means that the card is almost certainly from Ikoria. Also, there are 5 creatures, which implies to me that the card is a creature as well.
The Slayer is an interesting card that you have access to from the start of the game, implying to me that we're looking for a companion, a creature you start the game with. This narrowed my guess to one of the companions.
4 of them are R/W, and 3 of them have cycling, an activated ability. Zirda is the R/W companion and it reduces the cost of activated abilities--such as cycling--by

. Ergo, I think it's Zirda.
I could just be wrong, though. Notably, there are 4 enchantments, but enchantments are a) not creatures on Ikoria and b) not a big thing on Ikoria.