Chulane, Teller of Tales is a flavor win and a win condition for your Adventures deck
Chandra can flip into the planeswalker Chandra, Roaring Flame, and she has an emblem that can push out damage on my opponents' upkeeps
It can boost you in mana by a substantial amount if you can cast another ramp spell using the Dynamo mana, and its better evaluated along the lines of the Expertise cycle, or as a ritual of sorts
Having Hexproof is nice and makes you feel safe, but I ran Aegis of the Gods in Azor for years and it almost never saved me from anything, not only because having hexproof isn't as strong as it seems but also because people will want to kill it very quickly if they do need to target you
Most notably, Sisay's activated ability can be used if you pay one mana of each color, tutoring for a legendary permanent with a mana value less than Sisay's power, putting that card directly into play