If you do too much damage with the Gold Lion, Gyldygga will summon minions a turn earlier and won't attack the larger group. You'll want to make some adjustments in that case. As you can see in my video, I had to skip the Lion's third attack in order to not trigger it (which is weird since he's only damaging the Golem. I don't quite understand the AI logic, but it works).I got a crit off with Mjoll. I skipped my next attack to show that this isn't a requirement -- kind of annoying in terms of the demo tbh. He'll summon his idiots next turn and get off one more attack, but you should be able to finish him off immediately afterwards. If you don't have Bianca's multi-heal blossom node, that's totally fine. Seraphi or YT are also fine in her place -- you're really only interested in the Oomph from her. There really is a lot of room to play with this strategy.You can rearrange the units in the small group to try to slightly manipulate the AI. He'll still approach and multi-hit, but sometimes he'll move slightly differently to focus on certain (weaker) units.