Whatever the five abilities are, they should require mana of two colors (as this befits casualness) and should make it so that abilities of that permanent that share a color with the enemy color of the two colors used in that can't be played that turn. However, we don't want these abilities to be used multiple times per turn by one player. Something like this could do:
Mr. Untitled (name in progress)
5
While on the stack and in play, Mr. Untitled shares a color with every color of mana used to pay its mana cost, if you played it from your hand.
WU: Unless any player pays R or 2, counter target spell. Red activated abilities of Mr. Untitled can't be played this turn. Any player may play this ability, but only once per turn.
UB: Unless any player pays G or 2, target player discards a card. Draw a card. Green activated abilities of Mr. Untitled can't be played this turn. Any player may play this ability, but only when he or she could play a sorcery and only once per turn.
BR: Unless any player pays W or 2, Mr. Untitled deals 2 damage to target creature or player. Gain 1 life. White activated abilities of Mr. Untitled can't be played this turn. Any player may play this ability, but only once per turn.
RG: Unless any player pays U or 2, destroy target tapped land. Blue activated abilities of Mr. Untitled can't be played this turn. Any player may play this ability, but only once per turn.
GW:Unless any player pays B or 2, target creature gets +1/+1 and has first strike until end of turn. Black activated abilities of Mr. Untitled can't be played this turn. Any player may play this ability but only once per turn.
2/2
Some of the abilities might be more powerful than others, but I'm searching for a balance. What do you think?
Besides the fact that it's too long.