Also once the ability block happens thrawn can hit them with his basic again and stun them which works well against characters that counter because thrawn is beefy and can take a hit
Example zylo has retribution, thrawn shoots him and gives speed up and gets hit back no big deal to thrawn. Then you focus on Phasma with everyone else and when kylo goes he gets ability block when his turn ends after using his aoe to renew retribution. Then when thrawn goes he can stun kylo with his basic and all your characters can pound him without getting countered.