Imma Start i guess. . .
Jin (Shisa)
Shisa's are great pushers. Use their grabs and first charge to push off your opponents.
On Gorge of Oath, on either left most or bottom right most of the map, use "dash + Z +down" to do a roll move to get behind an opponent. As soon as u Z, press it again to start charging for first Skill, as soon as u pass the opponent release and kick out
On PVP, on any map when you find an opponent in a corner, use dragon kick. This will knock the opponent up the air. Use it consecutively and u will keep knocking the opponent up til he dies. dont Mess up the timing
Ronan (Spell Knight)
Great when being chased so attract lots of attentions :P
Easy Combo
VS Melee - use ragna bolt. This attack would temporarily stun them. Quickly jump forward and do a jump attack. This will stun them more. either grab or start a melee combo. Note: if you grab, Charge up for first charge, and release it when their about to stand up. If they dont use a wake attack, you should be able to hit em another 50 or more points of damage.
VS Range - try not to fight them 1v1. Try using Aegis Knight or Dragon knight. Aegis with proper timing can block off most attacks and dragon knights are much better in pursuing than spell or Aegis knight. Either go full offensive or defensive

Ronan is a defensive class so get better with Aegis its gonna help you out more in the long run.
Added delay and damage
Use ronan's buff skill, as soon as you receive the buff, before you become vulnerable again, you can already cast another skill.