Try to coordinate high-damage abilities with your allies right after Dr. Mundo uses his ultimate, but if you're unable to kill him quickly with burst he will heal through the damage.
Try casting Ignite when Dr. Mundo uses Sadism to negate a large portion of its healing.
The stats shown on this page clarify several critical Rell against Dr. Mundo counter stats that may help us realize the differences between the two. Rell’s KDA ratio ([kills + assists] / deaths) of NaN is more than Dr. Mundo’s KDA ratio of NaN, demonstrating that Rell may be more central to her team's team fighting capability than Dr. Mundo. This observation is in large part caused by the differences in assists.
Rell usually has a slightly smaller longest killing spree than her foe does. Typically, she takes less damage than Dr. Mundo. This often reflects different amounts of tankyness, but it can also indicate that the champ with increased health has less agility and thus is not able to escape additional harm when engaged or poked.
Both League of Legends champs are great champions. Both champs have their strengths, weaknesses, and counters. In the game's current meta, Rell usually loses when taking on Dr. Mundo, with a 47.0% win rate. Thus, Rell makes a bad counter for Dr. Mundo.
While Rell does have a lower win rate than Dr. Mundo, when facing one another, Rell also has a much lower level of difficulty that makes her a less complex character to pick up and master. You should be very concerned when picking Rell into Dr. Mundo.
Additionally, Rell also has a very large amount of CC and other utility, a similar amount to Dr. Mundo. This makes her just as valuable during teamfights, especially when fighting champions with a lot of burst damage.
While there isn't a single best champion overall in League of Legends, in Rell vs Dr. Mundo matchups, Dr. Mundo is the better champion with a much lower win rate, less champion complexity, and a similar amount of utility to help out your team members during late stage team fights.
Rell is a bad counter for Dr. Mundo. You will do well by focussing your tactics on keeping up your CS and taking out objectives. If you are able to do that, you should do very well as Rell against Dr. Mundo.
If you would like to learn all of the intricacies of Rell in order to counter Dr. Mundo during both the laning and mid / late game phases of League of Legends, you should keep reading to pick up a few extra tips and tricks for this matchup. If you mind the build and tips shown here, you will increase your win rate by a lot and be closer to League of Legends pro players.
Rell usually picks up a lot less CS relative to Dr. Mundo. Champs who on average don't take many minion kills typically don't have to have much CS to be valuable teammates, such as sup champs. They are capable of scaling well off of their abilities and first items alone. Yet, champs with a lot of CS, such as hyper-carries, usually need a lot of items to be effective. In either situation, try to exceed the values reported on this page to do well.
The most crucial items to use in your Rell versus Dr. Mundo build include Zeke's Convergence, Knight's Vow, and Celestial Opposition. When Rell bought at least these three pieces in her build, she did a lot better countering Dr. Mundo than with many other commonly used item sets. In fact, Rell had an average win rate of 47.0% battling Dr. Mundo with these items in her kit.
To have the greatest likelihood of coming out on top against Dr. Mundo as Rell, Rell players should equip the Glacial Augment, Hextech Flashtraption, Biscuit Delivery, Cosmic Insight, Bone Plating, and Unflinching runes from the Inspiration and Resolve rune sets. Out of all the rune builds players chose for Rell vs Dr. Mundo counter picks, this sequence of runes yielded the greatest win rate. In fact, these runes averaged a 47.0% winrate overall.
If you would like to get Rell vs Dr. Mundo tips and counter stats for a an individual player tier, feel free to select one from the selection menu above. At first, the statistics and build suggestions shown are computed using every game finished with these champions.