Sha Lin is the ultimate way of telling you to get out of the sky - and when you're on the ground, Impaler Arrow is a huge threat for you. Resilience will be necessary; a good Sha Lin will deal too much damage for Haven to be effective.
Chronos. There is rarely a reason to get anything else for Jenos except Chronos if you're intending to heal with him. If you find yourself being hard-countered get Chronos II then buy another item to properly defend yourself.
It’s hard to escape a good Skye. However, she has no mobility aside from movement speed, so if one jumps out at you, Flutter straight up and flick down shots on her before she can lock on again. Use Seedling if available.