Cleave (and especially Great Cleave) has always created problem situations. Attacks of Opportunity and Whirlwind Attack are two of the problems. Any feat or game situation that lets you get extra attacks on a large number of enemies or anything that gives you an extra bonus for killing an enemy (like Supreme Cleave) can get out of hand and result in completely illogical situations. I think the current rules for Supreme Cleave only allow you to take your normal 5 foot step once a round, but let you do it in the middle of a Cleave attack.
For those who defend the rules as logical, don't make me invoke blind kobolds (blind kobolds were also used to point out the silly state of Expert Tactician pre-errata). As Ridley's Cohort pointed out, illusions result in more silly situations (and might bring up the whole "cleaving through mirror images" debate). Tony Vargas also bring up the issue of the "bucket of snails" Great Cleave/Whirlwind Attack smackdown or its less abusive equivalent, summoned creatures.
I like the idea of Cleave acting as a sort of Combat Reflexes against weak enemies. I think I'd let you Cleave and use one and only one extra attack on another opponent who is also provoking an AoO (and Mobility and the relevant feats would still apply).
Consider the sorry case of a grand melee with 3 warriors- A, B, and C. All are at 1 HP, have attack bonuses high enough that they never miss, have Great Cleave, and are next to each other. C foolishly tries to drink a potion of healing, provoking attacks of opportunity. A and B both want to attack C and Cleave through him to kill the other one. Whoever gets the AoO wins the battle. If C were an ally of B, B would lose the battle unless he Cleaved his own friend to attack A.
For those who defend the rules as logical, don't make me invoke blind kobolds (blind kobolds were also used to point out the silly state of Expert Tactician pre-errata). As Ridley's Cohort pointed out, illusions result in more silly situations (and might bring up the whole "cleaving through mirror images" debate). Tony Vargas also bring up the issue of the "bucket of snails" Great Cleave/Whirlwind Attack smackdown or its less abusive equivalent, summoned creatures.
I like the idea of Cleave acting as a sort of Combat Reflexes against weak enemies. I think I'd let you Cleave and use one and only one extra attack on another opponent who is also provoking an AoO (and Mobility and the relevant feats would still apply).
Consider the sorry case of a grand melee with 3 warriors- A, B, and C. All are at 1 HP, have attack bonuses high enough that they never miss, have Great Cleave, and are next to each other. C foolishly tries to drink a potion of healing, provoking attacks of opportunity. A and B both want to attack C and Cleave through him to kill the other one. Whoever gets the AoO wins the battle. If C were an ally of B, B would lose the battle unless he Cleaved his own friend to attack A.