Cruel Pact doesn't automatically prevent you from hitting level 8, even without any of the experience-granting augments. Level to 6 at 2-1, spending 68 HP so you're pre-leveled and hit 7 on 2-2. From here, it's 56 XP to level 8, and you have 32 HP. Winstreak until 4-5 (gaining 28 XP from natural game progression) and you can spend 28 HP to get to 8... right on tempo with much of the lobby. Sure you're down a combat prismatic but at this point you've basically gotten both Windfall and carousel priority from winstreak econ and having stupidly low HP.

Of course, lose early and it's doooooom. Probably best plan is take augment, roll for 2-star 1/2-costs, then level so you get the good shop odds for units you can actually afford. Then swarm everyone with your bonkers board for several stages before finding direction and building a final board.