The entire season it is "play void or solar" to progress the milestone, meaning Titans being totally handicapped when it comes to "one and done" offensive supers. Warlocks Nova Bomb is Void, Warlocks Well of Radiance is Solar Hunters Blade Barrage is Solar and Bows are Void Titan has only Bubble as semi-offensive ability, since Thundercrash is Arc. It is like purposely forcing Titan players to play something less efficient for killing or clearing the way than any other class. And since people start playing at different times there is always one or the other Titan in your team not playing what would be more helpful because of not really thought out milestones.