Your favorite Fortress hero.

Well, if you're going for a light strategy, it's better to level up Helmar; Carli won't be able to handle a large map.

Why??? Helmar's specialization isn't better than Carli's!

After, for example, accelerating the overall stats and the retaliatory strike triggering, the appeal of Helmar's specialization ends; it's roughly the same as what Carli will do, but one turn later. In that time, Helmar is unlikely to gain a significant advantage thanks to his specialization.

And Carli, with a resurrection rune and a refreshing rune, remains in the fight for almost the entire decisive battle (if there is one) with her killer-harpooners.