Answered May 25th, 2019

Kawhi Leonard has scored 29.8 points per game when getting 9.0+ rebounds per game in the 2019 Eastern Conference Finals.

who was the last player with 29 ppg and 9 rpg in an eastern conference finals
Interpreted as:
Who was the last player with 29 or higher ppg and 9 or higher rpg in an eastern conference finals?
2018-19Leonard2017-18James2014-15James2011-12James29.833.630.333.6
NAMESEASONSERIESTMGPPPGRPGMPGAPGSPGBPG3PMFG%FT%TPGFGMFGA3PA3P%FTMFTAPFMINPTS+/-REBASTSTLBLKTOV
Kawhi LeonardKawhi Leonard2018-19Conference FinalsTORTOR629.89.541.34.32.21.01.844.288.53.29.521.55.334.49.010.22.824817913572613619
LeBron JamesLeBron James2017-18Conference FinalsCLECLE733.69.041.18.41.11.12.652.469.25.712.323.46.340.96.49.32.62882351163598840
LeBron JamesLeBron James2014-15Conference FinalsCLECLE430.311.038.29.31.50.51.343.872.73.811.526.35.025.06.08.32.51531214044376215
LeBron JamesLeBron James2011-12Conference FinalsMIAMIA733.611.045.83.91.11.31.352.765.03.412.423.64.429.07.411.42.63212355777278924
StatMuse has game-level data for rebounds per game going back to the 1963 playoffs.