itch.io

Yeah, there's a trade off for damage and speed - if you can get two smaller blows before the enemy goes, that's usually more efficient (especially if they can kill them off), and sometimes the health and positioning of the opponents means that you can only run the more powerful attacks on creatures that have very little damage, where as a smaller attack might take down a more wounded foe that's farther up the turn order.

The first two times you encounter the Chronotyrant he forces you to sacrifice a member of your party, erasing them from time itself, so you have to play through again while down a party member. The game is a balance of knowing which heroes are comboing well together, and which can be sacrificed to time so that the remaining heroes are more efficient (and so that the more powerful skills that come in waves 2 & 3 are placed on the heroes that are working well). 

The dialog at the start of the loop (when you're sent back in time) also changes, reflecting that with the loss of one of your heroes, you had to go through worse encounters to get to the fortress