I have completed all the Wild Brawl event tasks except for Revive allies 5 times (which does not award seals).
I have 43/44 Seals of Triumph in the Event Center.
However, the Wild Brawl event lasts until 02:59 on the 17th May so it’s possible that some of these tasks may reset and become available again before the event ends. If I recall correctly, this is what happened for the Conqueror event, i.e. you had to do some of the tasks twice over to maximise the event seals.
Instructions here…