Scenario:
Adam Warlock needs to collect a specimen from an Earth-like planet with a sentient plant species. If he brings the specimen a certain goddess will agree to be his mate, a goddess whose affection he deeply covets. Yet, collecting it means taking the life of these plant creatures.
Mantis happens to be on this planet and deems herself protector of the plant people. She will not let Adam leave with the specimen. They now do battle in a meadow on the planet.
70's Warlock would end up destroying that which they both sought in the course of an awesome fight with Mantis, and then fly off to mope about it.
90's Warlock would pull of a win by misdirection or giving Mantis a Hobson's Choice where she has to abandon her watch to avoid some greater problem.
Current Warlock, I'm thinking Mantis wins, but it's really too soon to judge.