It's a mode with no respawns that forces your teammates to revive you.I think every class has its uses. But if that warlock ram helm that blinds on Radiance works on guardians than you might see a few of those in Trials. I'm gonna run it with all three to get every piece of gear anyways. when the gear is shown in detail and I find a team and see what they are running, I'll decide what class to start with.
Every class can't resurrect like the Warlock.