Zilean will gain the cosmetic buff Armored Bear Hater ("In my day, we would never have allowed an armored bear into the League of Legends") if he and Volibear find themselves on opposing teams (references Tom 'Zileas' Cadwell being against an armored bear champion).
Both names may be free renditions of Greek Σ(εε)ιλᾶς S(ee)ilas, loaned from Aramaic שְׁאִילָא Šeʔila (cf. Hebrew Saul), from Semitic root š-ʔ-l "ask"
Zilean is a mage from Urtistan who discovered the way to manipulate time but was unable to save his city and his people. He is now trapped between timelines and left Urtistan to seek a way to cure his condition.
Zilean (and maybe even Bard) have probably already taken notice of Ekko's fiddling with the timeline by way of his Zero Drive.
Vel'Koz came across the ruins of Urtistan and discovered the magic within Zilean's former residence. The Eye of the Void is now resolute to find the Chronokeeper and disintegrate him to obtain the knowledge he possesses about time manipulation.