Just pulled a black dragonbound, typhoon on like my 5th re-roll...is that I a character I should be happy with or should I keep re-rolling for a horrus?
Personally, I'd keep rerolling until DKali if I were just starting. Not noob-friendly, but among the rarest pulls in the game and her active and awakenings make her useful on virtually any team, including being a key piece on some of the strongest teams in the game. Power creep has made it so you don't need a noob-friendly starter to get through much of the early game. Heck, pairing up with an Awoken Kagu is easy-breezy clears through a lot of the early game, whereas we used to pair up with Sirens for autoheals. Use your starter Dragon at worst and pair up with strong helpers to get you through much of the early game. You'll be racking up clear stones to get more REM pulls. You're sure to pull something better than your starter Dragon in no time. There are so many "good" leads now, that you have a high chance of pulling any one of them. When Horus came out, there weren't many/any monsters like it. But now you can pull Horus, Isis, LKali, Sakuya, DQ, Bastet, Sonias, Norns, etc.. You'll likely pull several/multiples of good leaders and only concentrate on a few of them. Then you'll be pining for that elusive DKali or other white whale when striving for those optimal endgame teams. Your starting roll is the only way to control what you get without getting super lucky or spending hundreds/thousands chasing that white whale.
NOTE: The above is coming from a long-time, hardcore PAD player, and is just my personal strategy if I had to start over. You may just be trying out the game and not even stick with it for very long, so hours of rerolling may not be worth it for you if you just want to get playing and try the game out.