Changes
Janna 📉 Janna's power shifted from 20 base damage on W to 20 extra shield on E. This is a small nerf for her because Janna's strength over other enchanters was her ability to roam quickly and set up plays reliably with W max. You still max W, or 3 W > 5 E.
Amumu 📈 Amumu got a 3 armor buff and 4 ad buff. This is a big buff to Amumu because he's a stat check champion. He can always force all ins and now he has the stats to back it up.
Karma 📈 A very small 5% slow buff to Karma Q and small buff to Mantra E. Overall Karma suffers right now from getting outscaled by other enchanters, but she still has a very strong lane.
Seraphine 📈 Seraphine was already feeling strong with E Max after the small rework, so any small buffs will push her from just playable to actually good.
NEW
Kennen's ultimate got a quality of life change that lets you cast ultimate while moving. Although it seems small, his winrate increased dramatically and he can most definitely play as an offmeta support this patch.