Discounting Hydraulic, i would suggest the Psychological tree set based simply on one strategy: work your way down to electrical storm, and also get terrify. these two skills not only will deal massive damage amounts with high instinct levels, but also both heal you (terrify) and recover your focus (electrical storm). used in conjunction with each other, since Terrify uses focus but electrical storm does not, you will have both endless heal and focus regen counters on you! however, you really shouldn't use other people's strategies from the comments and just try the game with your own method.
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