When I run Ares, I put Musashi on wing usually and let him heal himself.
These three are all solid to very good heroes. I think the question really boils down to play style.
- Inari only damages by tiles or minor minion pings. So principally a defensive hero there to keep your team alive and force your foe to either hold specials or risk losing the mana. This path requires patience and willingness to accept randomness (esp. with Misandra’s randomness added)
- Musashi is a straightforward, hard-hitting hero with solid tile damage. The self-heal trick is not so helpful in raids but great in titans, where the normal damage is rolling in.
- Onatel is a strategic, mana-delay hero. I wouldn’t say “situational “ in that she’s helpful in all situations. She requires more thought and planning than most to transform her from “okay” to “great”. She will be fabulous in challenge events. I’ve written a lot about her over here: Onatel, best hero idea - #22 by Kerridoc