EX Primal encounter design:

Phase 1: There are four things in a pattern to dodge, which are all attacks you've seen before.
Phase 2: There are now SIX things in a pattern to dodge, and one of the old things has a new twist!
Phase 3: Dodge all the things while killing the new targets that appear in time for the overdrive attack!
Phase 4: Can you dodge EIGHT THINGS!? Stand in the designated Safe Spot for your role and kill the adds! This phase repeats until the boss is dead. At sometime just after ten minutes, an enrage attack will kill the entire party if you suck.

EXTRA CREDIT! Randomly insert one of the following: Party members can fall off the arena, an add you SHOULDN'T kill, tank swap, repeated iterations of the Phase 3 ultimate attack.

Compared to the stuff in Coil, I gotta say, 'traditional' Primal battles feel lazy and formulaic. The ones that are kind of off the beaten path (Moggle Mog, Greg) tend to be interesting, but the mainline primals are just...ehh.