Having played and Directed this game all the way up to 10th level, and having seen every class in play (including the playtest summoner), I am confident that the hakaan null is the one ancestry and class combination with the highest optimization ceiling. It has plenty going for it.
21/9 Stamina, Density Ward, and Inertial Shield alone make a null exceptionally durable. Null Speed makes the character mobile, and all the more so as they gain levels and thus Agility.
Gravitic Disruption is apparently 1/creature/turn. With hakaan Forceful, that is a 3-square slide. Dance of Blows targets each adjacent enemy, comes with a slide of its own, and triggers Gravitic Disruption multiple times for multiple collisions.
The Ratcatcher title's Everybody Move! is fantastic on a null (metakinetic) due to tripling the targets of a heavily upgraded Knockback maneuver, which also triggers alongside Inertial Shield.
Reorder at 3rd makes a null, and, to a lesser extent, the rest of their party very difficulty to pin down with debilitating conditions. Also at 3rd, Synapse Field adds a considerable amount of damage when a party is focusing fire on enemies in the null field.
The null really takes off at 4th level, given Psionic Leap, the metakinetic tradition for Inertial Sink, and a 150-project-point Deadweight. This lets a null, as part of their movement, jump up and generate a free melee strike. (I have seen a few people raise an argument that reducing falling damage voids the Deadweight's benefit, but this does not seem to be a common interpretation.) Suffice it to say, this is rather strong.
The 2nd-echelon title Blood Magic's Blood Mage benefit applies to the null field.
