Bahamut can become permanently invulnerable and untargetable using the Ruby effect of Ice Floe Slippers + the Emerald effect of Baphomet's Cursed Necklace

[DeckardCainRPC]

STEPS TO REPRODUCE:

1. be bahamut. equip Ice Floe Slippers and put a Ruby in them. (i also recommend putting an Emerald in the boots as well, since the exploit is easier to accomplish with the 35% drift speed bonus.) also, equip Baphomet's Cursed Necklace with a Pristine or Perfect Emerald in it. Baphomet's Ruin buff will not activate until you have cast Mega Flare (R) at least once while the amulet is equipped; do so now, then either use -refresh or wait for Mega Flare's cooldown to expire.
2. face a direction that would allow Bahamut to execute Mega Flare's charge movement effect without hitting an obstacle that would stop it prematurely (such as a cliff or other impassable wall).
3. immediately after casting Mega Flare, double-rightclick any area around Bahamut except the direction in which he is charging. this will cause Ice Floe Slippers to activate, and Bahamut will drift quickly in that direction.
4. continue issuing these Ice Floe Slippers drift commands as rapidly as you can, taking Bahamut far away from the location that would otherwise have been the point at which Mega Flare's charge would have ended. observe that the Mega Flare charge buff is still on Bahamut's buff bar during this joyride. the Mega Flare charge buff makes him invincible and untargetable, and lasts either 10 seconds, or until Bahamut touches the pre-assigned point at which the Mega Flare charge would have ordinarily ended, had he not aborted it using Ice Floe Slippers. even while gliding around freely using Ice Floe Slippers, the player will note that a slight push force is being applied to Bahamut in an attempt to move him in the direction of the Mega Flare's intended impact point.
5. Bahamut can still cast Q, W, and R during a Mega Flare charge; the only caveat is that, in order to successfully cast Q, he must be facing the appropriate direction long enough to fully execute the spell's cast animation. as W and R do not require a target point, these can be cast freely at any time. E is unavailable because it cannot be cast while rooted.
6. because he can still cast R during an ongoing Mega Flare charge, if its cooldown is somehow refreshed, and its cast time removed, this would allow Bahamut to refresh the Mega Flare charge buff indefinitely. this is possible using the Ruin buff from Baphomet's Cursed Necklace, which removes the cast point on a hero's R ability, along with its Emerald effect, which lowers the cooldown of this effect from 12 seconds (which is two seconds longer than the Mega Flare charge buff's maximum duration) down to a comfortable 8 seconds with a Perfect Emerald.
7. if the player takes care to 1) avoid stepping on the intended destination of his most recent Mega Flare, accomplished by frequently issuing Ice Floe Slippers drift commands, and 2) re-casts Mega Flare during the 2-second window wherein Baphomet's Ruin buff is available and Bahamut still has the Mega Flare buff active, Bahamut will remain invincible indefinitely, until the player fucks up or triggers a cutscene.
8. a player with quicker fingers and better reflexes than mine might observe that Bahamut can pass through a single Wall of Impunity (Q) multiple times by abusing this exploit. this can be used to trigger the colossal R2 nuke repeatedly.