Is Thunderlords op or are other keystones just weak?

So playing lately all I see are 8-10 Thunderlords and some others (tanks with bond or supports with healing) I play a lot of all in champs so I never really took a big notice but I thought Id try using a dps champ other than brand and see if Deathfire would make someone like Malzahar burn someone down but sadly it didnt seem to be very good.