If its not clear, Van is calling Hexor brother, not Hal. The two halflings aren't related, but Van has spent too much time under Trelmarixian's patronage so likens the daemons to protective older brothers. Older brothers who kill for fun.
If we prep for a few rounds:
- Hal casts Mage Armour, Van casts Bears Endurance on herself and whistles for the Hell Hounds.
- Hal casts Cat's Grace on Van, Van casts Align Weapon on Il'Tara's primary.
- Hal casts Invisibility on Van, Van casts Instrument of Agony on either Il'Tara's primary weapon or Hexor's claws if natural weapons qualify.
- Hal casts Mirror Image on either Hexor or Van or Il'Tara.
If Hexor is going to dimension door straight to combat:
Hal casts Vanish. Van casts Bless on everyone and Rage on Hexor, the Hell Hounds, and Il'Tara (if she wants to be enraged).
If we regroup with Vexor, Ezra, and whomever first great.