In the recent test suit changes, Olaf's small rework made many people feel incredible, because from the reworked content, it is indeed a bit too OP, so designer Riot Axes posted some changes for him in the test suit on personal Twitter.
Olaf
【W】Base shield value decreased from 70/115/160/205/250 to 10/45/80/115/150, and set an upper limit for the shield, which is "30% current health"
[R] Passive resistance bonus decreased, weakening from 20/30/40 to 10/25/40
The attack damage bonus is also relatively weakened, from 15/20/25+30% attack damage to 10/20/30+25% attack damage
Another hero who changed is Zeli, this hero has attracted a lot of attention since it was launched, especially in the professional arena, but the recent version of the weakening also made her no longer favored, perhaps because of this, so in the latest test suit changes, fist has been strengthened for many of its small skills.