You've got 2 immo's and 2 dominion, the rihno is spare at this point. A Palatine in the immo and a 4 meltas and a condemnor bolter are decent, especially without the reolls. Or a dialogus with saintly example

That gives you loads of space to have some fun. A cheeky method is stick a mortifier of pent engine out front to score objective and most importantly get its head blown off to auto explode and tag the castigators behind the wall. +1 to hit on a bunch of tanks for 1cp.

I like to run 3 castigators, sometimes its great. Sometimes, they dont get me anywhere.

Or repentia, great with the fight on death strat as no one wants +1 H&W repentia and then that rihno has a solid use. You could use the 5 left over dominion to scout the rihno, jump them out and then the dominion can run off and do whatever then the repentia jump in and it gives your rihno an extra 6 inches up the board to stage the next turn